Indonesia’s national police chief said initial investigations showed that Tuesday's blast, which killed 10 people at the Marriott Hotel, could be linked to the Jemaah Islamiah (JI) group.
When asked if JI was responsible for the bombing, General Da'i Bachtiar said: "It is certainly heading in that direction."
The driver of the car, packed with explosives and fuel, was identified as Asmar Latin Sani, 28, from Lampung in the south of Sumatra island, Erwin Mappaseng, head of the police criminal investigation division, told reporters.
"He was known by two terrorist members who in the past we had arrested... He was certainly recruited by them," Mappaseng said.
But he avoided questions on whether the two detainees were members of the JI network, which has been blamed in last year's Bali bombings and linked to Al-Qaeda.
Although he did use JI terminology to describe the role of the three men.
"He (Asmar) was certainly recruited by this group. And certainly from the Bali terrorist group and their friends. But I didn't say they were members of which wakalah," Mappaseng said, using the JI word for a state-level cell.
Tuesday's blast killed 10 and
injured over 100 people
Mappaseng named the two "terrorist" detainees as Sardono Siliwangi and Mohammad Rais.
One day earlier, police released grisly photos of the reconstructed head of the suspected suicide bomber showing a youngish man with a small goatee beard.
Investigators have already highlighted similarities between Tuesday's bomb and the Bali nightclub blasts, particularly the composition of the explosives used in the latest strike.
A mobile phone was used to detonate the bomb, as in at least one of the Bali bombs. The Bali bombs were made from a cocktail made up essentially of potassium chlorate and TNT.
Police said the Marriott bomb contained TNT and a "black powder".
Tuesday's attack followed a spate of global terror warnings, and officials have said they fear more strikes.
One foreigner, a Dutch banker, was among the 10 killed in the Marriott attack. Singaporeans, Americans, Australians and several New Zealanders were among the 150 injured.