"As a mark of respect for the victims of the senseless acts of violence perpetrated... in Nashville", President Joe Biden has ordered, external US flags to be flown at half-mast until the end of the month.

This means flags at all public buildings and grounds, as well as at American embassies, must be flown at "half-staff" (to use the US term).

The order remains in force until sunset on Friday.

Avery Myrick's mother is a pre-school teacher at Covenant School. Though she was in contact with her mother, she still feared for her safety.

Myrick told, external a local NBC station her mother was hiding with her students.

“She said they were hiding in the closet, and there was shooting all over,” Myrick said.

“[She said] they had potentially tried to get into her room and just that she, like, loved us.”

A resident who lives near the school spoke, external to a local ABC station about what she heard.

Kathy Thoreson told a local reporter she first thought the noise was roofers, but then noticed helicopters in the air.

"We knew then it wasn’t roofers," she said.

"The first about eight or 10 shots were very loud."

"I have four grandkids here," she said choking up. "I mean, I can be thankful, but I am so sad for these parents and kids.

"It’s very tragic. It’s two blocks from our house. It could happen at any school. It’s very tragic. It really is."

Nashville Police Chief John Drake told NBC News that the suspect in the attack might have been motivated by unspecified "resentment".

"There's some belief that there was some resentment for having to go to that school,” the police chief told the network's evening news host, Lester Holt.

Drake said the shooter "targeted random students in the school, just whoever, and persons, whoever she came in contact with, she fired rounds".

Drake also said the shooter’s so-called manifesto mentioned multiple locations - Convenant School being one of them.

Image source, EPA-EFE/REX/Shutterstock

Last year, in an effort to stem America's escalating gun violence, President Biden passed a landmark gun-control legislation.

It imposed tougher checks on young buyers and encouraged states to remove guns from people considered a threat.

But months later, the US Supreme Court delivered a ruling that could make it harder for states to pass gun restrictions.

Over the years, lawmakers have proposed increasing background checks, passing red flag laws, and banning assault weapons in an attempt to curb gun violence in America. But nearly every proposal has been met with intense pushback.

Here's a look at some solutions that gun-control advocates and gun-rights proponents say could help stop escalating gun violence -- and whether or not they're likely to work.

Image source, Reuters

Schools and churches have scheduled vigils in the aftermath of today's school shooting that left six dead, along with the shooter.

• Bethlehem United Methodist Church is hosting a vigil at 6pm local time (23:00 GMT)
• Belmont United Methodist Church will host a vigil at 6:30pm local time
• The Christian school Lipscomb University announced a prayer event at 7pm local time
• Christian singer Lauren Daigle postponed a concert to instead host a community wide prayer vigil at Marathon Musical Works

The Community Foundation of Middle Tennessee has established the Caring for Covenant Fund. Donations will go towards supporting those affected by the shooting.

Image source, Getty Images

Dozens of emergency response vehicles zoomed through the streets of Nashville on Monday morning, causing shock among local residents like Jozen Reodica, who witnessed some of the chaos.

Reodica told the Associated Press that her building was placed under lockdown and she heard police sirens and fire trucks nearby.

“I thought I would just see this on TV,” Reodica said. “And right now, it’s real.”

Covenant School parents described the tense moments as some waited an hour or longer to be reunited with their children at Woodmont Baptist Church, the designated reunification site.

Sarah Shoop Neumann messaged the BBC over Facebook at 13:28 local, three hours after the deadly school shooting ended.

“We don’t know who is dead,” she wrote. “Waiting for our kids.”

Students were bused to Woodmont Baptist, where local news reported, external children sticking their heads and arms out of the bus window, yelling and waving to parents upon arrival.

Nashville police have given their second update on the deadly shooting at a private Christian primary school a short while ago. This is what we learned:

• The shooter was 28-year-old Audrey Hale, who police said identified as transgender
• They believe she had been a student at the school at some point
• Police found a manifesto and maps drawn of access points to the school
• They believe she gained entry by shooting through a door at the school
• She had two 'assault-style' weapons and a handgun, and at least two were purchased legally
• Police did not name a motive, but said they had theories
• They were continuing to search a residence on Brightwood Avenue
• Police said the shooter had identified a second target, not a school, but decided there was too much security at the second location

A mother of two children at the Covenant School described Katherine Koonce, one of the three adult victims in today's shooting, as "a saint".

"She did so much for those kids," the woman told the BBC over Facebook. "And now gave her life protecting them."

"She knew every single student by name. ... She did everything to help them when families couldn’t afford things, it didn’t matter. She found ways for them to stay."

Koonce was Head of School at the private Christian institution, according to the Covenant School's website.

Image source, Getty Images

Students in the US are prepared from a young age on how to respond to mass shootings.

The Covenant School is no exception - the private school held an active shooter training programme last year to prepare for such an event, according to local Nashville outlet News Channel 5.

When a gunman opened fire last month at Michigan State University in Lansing, Michigan, the school sent a message to all its students, urging them to "Run, Hide, Fight".

It was not just a call to action, but a reminder of a government-funded active-shooting programme that is provided to all students.

The message sparked horror from some parents who were disturbed by the idea their children would have to spar with a gunman.

But active shooting and criminology experts have told the BBC the messaging is an important reminder of the most effective way to reduce mortalities and stay alive in the event of a mass shooting.

"It's three simple verbs that trigger the memory of the training you received, and which tell you that fighting is a last resort and running is a good first resort," said Katherine Schweit, a retired FBI agent.

You can read more about what experts are telling students on how to survive mass shootings here.

The 28-year-old female shooter accused of killing six people at Convenant Day School was allegedly armed with two "assault weapons" and two pistols, according to police officials.

Although there's a lot of debate over what classifies an "assault weapon", the US Bureau of Alcohol, Firearms and Tobacco (ATF) maintains a list , externalof military-grade weapons that has the ability to automatically or semi-automatically fire bullets.

More than 85% of public mass shootings have involved such weapons, according to the Giffords Law Center to Prevent Gun Violence. , external

But despite their increased use in mass shootings, US lawmakers have resisted efforts to ban the semiautomatic weapon.

In recent years lawmakers have faced stiff hurdles to any proposal to ban the weapons and have been unable to pass federal legislation. But a Supreme Court ruling could soon decide if these bans are constitutional.

Police said the shooter used two "AR-style weapons" as well as a handgun, and that at least two of the guns were obtained legally and locally.

They are currently searching a residence on Brightwood Avenue.

Police have not given a motive, but said they have found a manifesto.

They named the shooter, who died at the scene, as Audrey Hale, who they said identified as transgender

Police say the shooter, a 28-year-old white woman from Nashville, gained entry to the school by shooting through a door.

They named the shooter as Audrey Hale.

During their investigation they discovered a "manifesto" and a "map drawn out of how all this was going to take place".

Police said they have a theory about motive, but they cannot confirm it at this time.

Earlier, they confirmed the names and ages of the six victims.

Image source, Reuters

At the briefing now, Nashville Mayor John Cooper said he was "overwhelmed by the loss" of life in the shooting.

"14 minutes from start to finish" was all it took to take the lives of six people, he said.

"Those guns stole precious lives from us today from Nashville. In this dark hour let us support each other, let us hug our children a little bit closer tonight."

Nashville police have identified the six victims fatally shot by the shooter at The Covenant School as:

• Evelyn Dieckhaus, age 9
• Hallie Scruggs, age 9
• William Kinney, age 9
• Cynthia Peak, age 61
• Katherine Koonce, age 60
• Mike Hill, age 61

In the United States, female mass shooters are incredibly rare.

Only four of 191 mass shooters were women, according to The Violence Project, a research centre that tracks and analyses deadly shootings across America.

In the five years since the Parkland massacre, there have been more than two dozen mass shootings in the United States. In the aftermath, shock and grief can quickly give way to a single question: Why?

According to experts, there is an eerily similar trajectory among these shooters, from childhood trauma, to run-ins with the law, a desire to end the life of the subject and then, finally, a tragic desire to end the lives of others.

Find out more about the warning signs of mass shooting.

Image source, BBC News

As we wait for more information here is some information from an earlier press conference.

Nashville police chief John Drake detailed the police response and said he was moved to tears by this the tragedy.

Nashville police will be providing another update at 5pm local time (22:00 GMT).

So far, they have identified the shooter as a 28-year-old white woman from the Nashville area.

Police have also said she may have been a former student of The Covenant School, a private primary school where the shooting took place, but that was based on "initial findings".

They have not released her name, or the names or ages of the six victims.

Three children and three staff members were killed.

A woman jumps in at the end of a press conference by officials to say that she survived a previous mass shooting in Illinois last year.

Ashbey Beasly said was visiting family in Nashville.

Following today's shooting she said: "How is this still happening?"

A distressed parent told , externalNBC News how she learned about the shooting.

The unidentified mother said she originally thought it was a bomb threat.

“There were so many police cars and then the ambulances started coming away from school and that’s when I heard it was school shooting."

“There’s no words,” she choked out through tears.

She explained they were not letting parents in, but that parents were running up the street towards the school.