At least seven people have been killed in a series of coordinated bomb and gun attacks in central Jakarta, Indonesia's police told Al Jazeera, as blasts rang out of the capital's downtown area.

An unknown number of people were injured in the security operations at the Sarinah shopping complex on Thamrin Street in Jakarta's central district on Thursday.

Police said the attack has ended and that security forces are in control of the area.

Earlier police reports said five gunmen were killed and that another five policemen and seven civilians were also dead. Police later revised the toll to a total of seven, including four attackers.

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

Earlier, tweets from the account of Jeremy Douglas, regional representative of the UN office on Drugs and Crime for Southeast Asia and the Pacific, described a bomb and "serious" exchanges of gunfire on the street outside his office.

Al Jazeera's Step Vaessen, reporting from Jakarta, said a police post was destroyed in a grenade blast and that sporadic gunfire was heard in the downtown area of the capital.