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.
 
"Six gunmen on motorbikes entered the downtown area carrying long rifles, shooting into the crowd, with some carrying explosives," Vaessen said. "One of the gunman shot a police officer from close range."
Some gunmen on motorbikes reportedly escaped, police sources told Al Jazeera.
"Witnesses told Al Jazeera that they found nails on the streets near the affected area, indicating that the fragments came from the explosives used in the attacks," Vaessen said.  
The attacks caused panic and prompted a security lockdown and enhanced checks in several areas in the city of 10 million.
"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," our correspondent said. 
Police gathered outside a restaurant near the scene of an attack in central Jakarta [Beawiharta/Reuters]

Presidential statement
Indonesian President Joko "Jokowi" Widodo, who was 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.
"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 that he was cutting short his visit and returning to the capital.
"This act is clearly aimed at disturbing public order and spreading terror among people," Jokowi said in statement on television.
'Credible threat'
No one has claimed responsibility for the attacks, but police have confirmed to Al Jazeera that the Islamic State of Iraq and the Levant (ISIL) group had made specific threats before Thursday's attacks.
Indonesia, the world's most populous Muslim nation, has been a victim of several bombing attacks in the past, claimed by Islamic groups.
Thursday's attacks, however, were the first major incidents in Indonesia's capital since the 2009 bombings of two hotels that killed seven people and injured more than 50.
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.
The attacks in the Sarinah area in downtown Jakarta also damaged a Starbucks [Al Jazeera]