|Police locked down the Sarinah area in downtown Jakarta, which was hit by several explosions [Darren Whiteside/Reuters]|
At least four people have been killed in a series of explosions in central Jakarta, Indonesia's police told Al Jazeera, as gunfire rang out of the capital's downtown area.
An unknown number of people were injured in the ongoing attacks at the Sarinah shopping centre near the presidential palace in the centre of Jakarta.
One of the dead was believed to be policemen, police told Al Jazeera.
Al Jazeera's Step Vaessen, reporting from Jakarta, said a police post was destroyed in a grenade blast and that a gun battle was ongoing in the downtown area of the capital.
"About 10 to 15 gunmen on motorbikes entered the downtown area carrying long rifles, shooting into the crowd, with some carrying explosives" Vaessen said.
Several gunmen of two motorbikes reportedly escaped, police sources told Al Jazeera.
"It is believed that several gunmen are currently hiding in the Jakarta Theatre, a cinema near the affected area. A lot people are believed to be still inside. Police has the building surrounded. The situation there is very unclear.
"The attacks have caused a lot of panic and the area has been locked down by police.
"The police are still investigating so we don't know how and why the attack happened. There were at least six explosions, and so far it looks like the police was the target."
A witness told Al Jazeera that one of the gunman shot a police officer from close range.
No one has claimed responsibility for the attack, however, police have confirmed to Al Jazeera that the Islamic State of Iraq and the Levant (ISIL) group had made specific threats towards targets in Indonesia recently.
Indonesian President Joko "Jokowi" Widodo, who is on a working visit in West Java town of Cirebon, has ordered security forces to hunt down the perpetrators and their network behind the attacks in Jakarta.
"I have received reports some time ago about the explosion in Thamrin street Jakarta. We express condolence to those who became victims, but we all also condemn the attack that caused restless among the community," Jokowi said.
He said he had ordered the national police chief and the minister for political and security affairs to hunt down and capture the perpetrators and those in their network.
Jokowi said he was cutting short his visit and retuning to the capital.