Four attackers have been shot dead and police are securing a building where the attackers were holed up, said Reuters news agency quoting police spokesman Iqbal Kabid.

He said that the gun battle took place at a cinema in the same building as a Starbucks outlet that was attacked. 

Journalist Beh Lin in Jakarta is reporting that paramedics and more security officials have arrived.

If you are just joining our live coverage here is what we know 

• A series of blasts have hit the Sarinah intersection, in the commercial heart of Indonesia's capital. Reports say at least six people have been killed.
• A number of people attacked the police box in the centre of the intersection with explosives, possibly grenades.
• More explosions were seen at nearby buildings including at a Starbucks outlet.
• Armed police have sealed off the area, and are engaging in a gun battle with remaining perpetrators. Armoured military vehicles have been seen coming into the area.
• The US embassy, near Sarinah, has warned its citizens to stay away from the area.
• Police have denied reports of more explosions at another district known as Palmerah.

The BBC's Kiki Siregar from the Indonesian service says that hundreds have already been evacuated from the site, but some may still be trapped in the area sealed off by the police.

Indonesia's TV1 news outlet, which is live broadcasting from the scene, is saying that six people are now dead - three policemen and three civilians.

Twitter users in Indonesia are sharing pictures like this one, condemning today's blasts 

Armed police are still engaged in a sporadic gun battle with the perpetrators who are holed up in at least one building near the blast site.

Image source, AP

Indonesian President Joko Widodo has said he is cutting short his visit to the West Java town of Cirebon and returning to the capital. He was quoted by AP news agency as saying: "We express condolence to those who became victims, but we all also condemn the attack.'' He has ordered security forces to hunt down the perpetrators.

Although it's unclear who is behind these attacks and too early to say who might be responsible, Jakarta police have been saying for sometime that an attack on Indonesian soil may be just a matter of time. The initial nature of these attacks appear designed to illicit maximum damage.

Indonesian motorcycle taxi service Go-Jek is offering free rides to those needing "evacuation to safer areas".

The army has been called in and several tanks have rolled into central Jakarta near the blast site, reports the ABC's Indonesian bureau chief Samantha Hawley.

The latest pictures are coming in as explosions and a gun battle between police and the perpetrators rock central Jakarta, see them here.

Jeremy Douglas, who works in a UN building near where the explosions happened, describes what he saw. 

He tells BBC World TV: "We were pulling into the office, we got out of the car and then an explosion occurred maybe about 150 metres away. 

"Then we ran into the building. We heard a third explosion. We got up to our office on the 10th floor and we heard a fourth (explosion), a fifth and a sixth and there is gunfire going on in the street right now." 

Wall Street Journal reporter Resty Woro Yuniar, external posted this picture of heavy police presence near the Sarinah shopping mall.

This report, external by Indonesian news outlet Detik says that the stand-off is taking place at the Cakrawala building in central Jakarta, and that the blast perpetrators, who are armed, are holed up on the fourth level.

The US embassy has issued this alert for its citizens:, external "This emergency message is being issued to advise all US citizens to avoid the area around Sari Pan Pacific Hotel and Sarinah Plaza on Jalan Sudirman Thamrin, in downtown Jakarta.  Preliminary reports indicate an explosion and gunfire has occurred in the general vicinity and situation continues to unfold."

Jeff Hutton, a Christian Science Monitor journalist, is at the scene. 

He tells BBC's Newsday programme: "It still seems to be very much a situation in flux. Police are doing their best to secure the area. They believe that there are still gunmen inside the Sarinah mall."

National police chief Anton Charliyan has told Metro TV that there was no explosion in Palmerah. There were earlier unconfirmed reports that there were other blasts in the area, which is a separate neighbourhood from Sarinah in Jakarta.

Twitter users in Indonesia are condemning the blasts in Jakarta, by using the hashtag #KamiTidakTakut, external, meaning "we are not afraid".

Indonesia's Metro TV says that the perpetrators behind the explosions are allegedly hiding in the Djakarta Theatre, while news outlet Detik is reporting that police are surrounding the theatre.