Smoke billowing from the scene of explosions in Jakarta, Indonesia. (Twitter Pic)

At least seven 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 security operations at the Sarinah area near the presidential palace in the centre of Jakarta on Thursday.

At least four of the gunmen were among the dead and at least one policeman was killed, police told Al Jazeera. A Dutch national, who was working for the United Nations, was also among the dead.

Al six blasts occurred in the central business district, about 50 metres apart, which also houses a United Nations office.

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 on 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.

Presidential statement

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.

Thursday’s attacks were the first major security incidents in the capital since the bombings of two hotels in 2009.

“This act is clearly aimed at disturbing public order and spreading terror among people,” Jokowi said in statement on television.

The attacks come two days after jailed Islamic leader Abu Bakar Bashir appealed to a court to have his conviction for funding a “terrorist training camp” overturned.

The 77-year-old leader of the Jemaah Islamiyah network filed a judicial review of his 2011 conviction, when he was sentenced to 15 years in jail for setting up the camp in Aceh province. A higher court later cut the sentence to nine years. (Al Jazeera)