At the news conference earlier today, Kerr County Judge Rob Kelly - the top official in the county - was pressed as to why the camps along the Guadalupe River weren't evacuated ahead of the flood.

"We didn't know this flood was coming. Rest assured, no one knew this kind of flood was coming," Kelly responded.

He later added "we do not have a warning system" in the area, which has regular floods.

He said what happened on Friday "far" surpassed a flood in 1987, which resulted in the deaths of 10 teenagers on a church camp bus near the town of Comfort, south of Kerr County.

Image source, Eric Vryn/Getty Images

A number of Fourth of July celebrations have been cancelled in Texas due to the deadly floods in part of the state.

Many Americans celebrate the country's Independence Day by attending fireworks displays and barbecues.

Kerrville, in the flood zone region, cancelled its 4th on the River Festival.

The city of Boerne, south of the Kerr County flood zone, also cancelled its celebration because many of its emergency services staff are helping with flood search and rescue.

The heavy rains also affected festivities in Austin and a number of other cities across the state.

Angélica Casas
Reporting from El Paso, Texas

Image source, Eric Vryn/Getty Images

The Kerrville Breaking News group on Facebook is a forum where locals often post restaurant recommendations, upcoming events and resources in the area.

Over the last 12 hours, it’s instead been inundated with posts from families who have relatives unaccounted for from the flooding, and links to news stories about the catastrophic weather that’s hit Kerr County.

A pleading mother shared that she has not been able to get in touch with her daughter and son-in-law, whose home was swept away from a road near Kerrville Lake.

One woman in Austin, Texas posted that her grandparents living along the Guadalupe River had not been heard from since yesterday.

Others from around the state have shared photos of family who had last been at a local camp for caravans and motorhomes.

Texas officials said earlier that the White House had been in contact with the state to offer assistance.

In a social media post this evening, a spokeswoman for Homeland Security Secretary Kristi Noem said she's activated the US Coast Guard and Fema resources "to help get these girls to safety".

"Pray for Texas and these beautiful young girls," Tricia McLaughlin wrote, referring to the roughly 20 girls missing from a local summer camp following the flooding.

Searches are under way in the US state of Texas, after flash floods - here's what we know so far:

• Authorities say 13 people have been killed during severe weather and flooding in Kerr County, Texas
• Others, including around 20 children who had been at summer camp, remain unaccounted for
• Within 45 minutes the Guadalupe River rose 26 feet (8m) causing a "destructive flood", Texas Lieutenant Governor Dan Patrick said in a news conference
• Patrick said a massive search is under way in flood zones, including helicopters, nine rescue teams and people on the ground. It will continue overnight
• He said the number of people confirmed dead is expected to change in the coming hours
• Many roads in the central Texas region are currently impassable, delaying the reunification of young campers with parents

We're continuing to gather the latest updates on this story, stay with us for any new developments.

Angélica Casas
Reporting from Texas

I’m in San Antonio, Texas, just two hours shy of Kerr County, the epicentre of the catastrophic flooding.

Kerr is right in the heart of the Texas Hill Country, a hot spot for tourists and campers because of its scenic rolling hills, countless rivers and lakes and abundance of wineries. It’s a getaway destination for many of us in Texas looking to escape the city to bask in some nature.

While flooding can be common in this area, particularly along the Guadalupe River, the astonishing amount of rain that has hit in such little time is nothing like the area has experienced in decades.

It took the region by surprise, and became the worst case scenario for campers staying near the Guadalupe River, likely celebrating the 4 July Independence Day holiday weekend.

At a news conference earlier, Texas Lieutenant Governor Dan Patrick said a massive search was under way in the flood zones.

That included 14 helicopters, 12 drones and nine rescue teams with around 500 people on the ground.

Another official has said that search efforts, which began early in the morning, would continue through the night.

We can now bring you further details from statements made by authorities.

Texas Lieutenant Governor Dan Patrick held a news conference on Friday.

"Within 45 minutes, the Guadalupe River rose 26 feet and it was a destructive flood - taking property and sadly lives," he explained.

Some children remain unaccounted for where they had been attending a summer camp.

"That does not mean [the missing children] have been lost. They could be out of communication," Patrick added.

Governor Greg Abbott said Texas was providing "all necessary resources to Kerrville, Ingram, Hunt and the entire Texas Hill Country dealing with these devastating floods".

Meanwhile, the Texas Department of Agriculture Commissioner has warned local residents to follow local emergency warnings and to not attempt to drive through flooded roads.

Flash flooding has swept through Kerr County in Texas.

Dramatic pictures show flood waters rushing into homes and rising high into the trees.

Authorities have said thirteen people have died in Kerr County in the US state of Texas amid a bout of severe weather and flooding.

Others remain unaccounted for - including around 20 children who had been at a summer camp.

"That does not mean [the missing children] have been lost. They could be out of communication," acting governor Dan Patrick has said.

It follows the Guadalupe River rising by 26 feet (8 metres) within 45 minutes - a flood that has destroyed property and resulted in deaths, authorities have said.

We will have more details on this with you shortly - stay with us.