A series of bomb blasts have rocked the Indonesian capital, Jakarta, with continuing gunfire and reports of further explosions.
At least six people have been killed by the blasts, say police, which hit locations including a shopping centre close to UN offices.
Police say at least four suspected attackers are dead. It remains unclear who was behind the assault.
President Joko Widodo has called for calm but condemned the “act of terror”.
“We all are grieving for the fallen victims of this incident, but we also condemn the act that has disturbed the security and peace and spread terror among our people,” he said.
National police spokesman Anton Charliyan told local media police officers and civilians were among the dead and that no arrests had been made.
Images from Jakarta showed several bodies lying on the road outside a cafe and police police, as well as seriously injured people being carried away.
Indonesia has been attacked by Islamist militant groups in the past and was on high alert over the new year period after threats from the so-called Islamic State (IS).
Mr Charliyan said while it was not yet clear who carried out the attack, IS had warned of a “concert in Indonesia” which would be international news.
‘Gunfire right now’
The attack began with initial blasts outside the Sarinah shopping centre in Jakarta, followed by more than an hour of gunfire and continuing reports of further explosions.
Armed police, snipers and armoured vehicles are on the streets of the capital.
BBC Indonesian reporter, Jerome Wirawan said police had cordoned off the area around the shopping centre.
A UN official, Jeremy Douglas, told the BBC he was about 150m away from one of the first blasts near the UN’s building.
“Then we ran into the building. We heard a third explosion. We got up to our office on the tenth floor and we heard a fourth, a fifth and a sixth.”
In one incident eyewitnesses say at least three attackers entered a Starbucks cafe in the area, which is close to several embassies, and detonated explosives before opening fire.
A Reuters photographer said police appeared to be aiming guns at a man on the roof of the building.
‘Maximum damage’: Karishma Vaswani, BBC News
Jakarta police have been saying for some time that an attack on Indonesian soil may be just a matter of time.
Although it isn’t yet clear who is behind these attacks, they appear designed to inflict maximum damage.
Although no-one has claimed responsibility for these attacks, in the last few years there have been anywhere between 150-200 Indonesians who it is thought have gone to Syria to fight with IS.
Many have since returned and the police have thought that they might be preparing an attack in Indonesia.
Indonesia is the world’s most populous Muslim nation but by and large is secular, although in recent years the threat of radicalism has remained high as small networks of militants are still thought to be operating in the country.
Source: BBC: http://www.bbc.com/news/world-asia-35309195