Investigators examined body parts and other forensic evidence in an attempt to identify the two bombers. They confirmed the death of a third Australian in Friday's blasts - bringing the number of confirmed foreign fatalities to at least four - and said their earlier toll of eight had included the two bombers.
Terrorism experts said they strongly suspect the attacks were orchestrated by Noordin Top, a Malaysian fugitive who heads a breakaway faction of the Southeast Asian militant network Jemaah Islamiyah.
"I'm 200 per cent sure this was his work," said Nasir Abbas, a former Jemaah Islamiyah leader turned police informant who has worked with police on investigations into Indonesia's last three terrorist attacks.
The bombers posed as guests attacked the J.W. Marriott and Ritz-Carlton hotels in Jakarta, setting off a pair of blasts that wounded more than 50 people, authorities said.
A police investigator also told The Associated Press on Saturday that Noordin was the most likely suspect.
"Considering the target, the location and content of the bombs, it was clearly the work of Noordin," the investigator said, declining to give his name because he wasn't authorized to speak to the media.
He said police had confiscated handwritten notes, a cellphone and a bomb encased in a laptop computer from room 1808 of the Marriott, where the bombers had apparently prepared for the blasts.
The investigator said a hotel receptionist told police that the man who checked into the room gave his name as "Nurdin." He gave a $1,000 cash deposit because he had no credit card, he said.
Authorities have not officially named a suspect, but suspicion quickly fell on Jemaah Islamiyah or its allies. The al Qaeda-linked network is blamed for past attacks in Indonesia, including a 2003 bombing at the Marriott in which 12 people died.
The heads of four of the bodies recovered from the blast scenes - two at each hotel - had been blown off, the police investigator said.
It has been nearly four years since the last major terrorist attack in the world's most populous Muslim nation - a triple suicide bombing at restaurants on the resort island of Bali that killed 20 people.
Friday's strikes raised questions about security gaps at high-end hotels, which have become popular targets for militants in recent years, most notably in Mumbai, India, where attacks in November killed 164 people.
Security was boosted at sites frequented by Westerners across the Indonesian capital of 13 million, where hotels already screen every vehicle, and guests enter through metal detectors. However, many visitors say searches are often cursory.
The attack occurred as the Marriott was hosting a regular meeting of top foreign executives of major companies in Indonesia organized by the consultancy firm CastleAsia, said the group, which is headed by an American.
Officials have identified five of the dead - three from Australia, one from New Zealand and one from Indonesia. The Health Ministry initially reported the death of a Singaporean, but police said they were unable to confirm that.
Australian Foreign Minister Stephen Smith said Saturday after meeting with his Indonesian counterpart that the dead included Trade Commission officer Craig Senger.
"The hearts of our nation go out to those families," he said.
Family members of another Australian victim, Perth businessman Nathan Verity, were expected to identify his body Saturday before taking it home to be buried, the Australian Associated Press reported, quoting a family friend.
The dead New Zealander was identified by his employer as Timothy David Mackay, who worked for cement products manufacturer PT Holcim Indonesia.
Officials said 17 foreigners were among the wounded, including eight Americans and citizens of Australia, Canada, Hong Kong, India, Italy, the Netherlands, Norway, South Korea and Britain.
Six of the injured were being treated for burns and shrapnel wounds in Singapore, a 90-minute flight from Jakarta, said International SOS, a provider of medical assistance.
None of the Americans suffered life-threatening injuries, State Department spokesman Robert Wood said.
Two of those wounded at the Ritz-Carlton were employees of Phoenix-based Freeport McMoRan Copper&Gold Inc., said Bill Collier, a company spokesman. He declined to identity the two men or their nationalities, citing company policy, but said their injuries were not life-threatening.
The blasts at the high-rise hotels, located side-by-side in an upscale business district in Jakarta, blew out windows and scattered debris and glass across the street, kicking up a thick plume of smoke.
The attackers evaded hotel security, smuggling explosives into the Marriott and apparently assembling the bombs on the 18th floor, where an undetonated device was found after the explosions.
Security videos captured the moment of the explosion in the Marriott. The brief, grainy images show a man wearing a cap and pulling a bag on wheels walking across the lobby toward the restaurant, followed by a flash and smoke filling the air.
The Manchester United football team cancelled a visit to Indonesia in the wake of the attacks. The team had been scheduled to stay at the Ritz-Carlton on Saturday and Sunday.
In October 2002, two Bali nightclubs were attacked, killing 202 people, many of them foreign tourists. Jemaah Islamiyah was accused of responsibility.