Indonesian police have stepped up their search for clues to the identity of three suicide bombers who carried out Saturday's deadly attacks on Bali.
More than 100 people were injured in the blasts
The police hunt continued as the Australian government warned of further possible attacks on the tourist island.
A key figure linked to previous bomb attacks in Indonesia, Abu Bakar Ba'asyir, issued a statement condemning Saturday's bombings.
Twenty-two people, including three bombers, died at three restaurants.
Police said they had been questioning two people since Sunday in connection with the attack, but there was no "strong indication" they were involved.
Bali police chief I Made Mangku Pastika released few details about the two men, who he said were not under arrest, but did say they were not Balinese.
Police are recovering scraps of the explosive devices as part of their investigation, and have also found shreds of a black bag and jeans, and two wallets believed to have been used by the bombers, said police spokesman Brig Gen Sunarko Danu Artanto.
A doctor in northern Australia, where some of the victims were evacuated to, has told ABC radio that his staff had removed bags of shrapnel from people injured in the bombings, and these would be handed to Indonesian police.
Mr Pastika appealed to the public to come forward with information, following the publication of photographs of the bombers' severed heads.
"We need the participation of all people in Indonesia," he said. "The pictures of them [the attackers] are clear, and they are easy to recognise."
Australia's foreign ministry warned on Tuesday that more attacks could follow, naming one area which may be particularly at risk - Seminyak - and urging Australian nationals to consider leaving Bali.
"Media have reported further general and specific bomb and terrorist threats and anonymous tip-offs in the wake of the 1 October bombings," the ministry said in a statement.
"While this information cannot be corroborated, Australians should be aware that the Seminyak area in Bali has been mentioned as a potential target for terrorist attacks," it said.
At least two Australians were killed in the attacks, and the foreign ministry said it had "grave fears" about two more.
Hunt for masterminds
The Indonesian authorities have said they want to find two Malaysian fugitives suspected of masterminding other attacks in Indonesia.
They are Azahari Bin Husin and Noordin Mohamed Top - suspected leaders of militant group Jemaah Islamiah who have been on Indonesia's most wanted list since the Bali attacks of 12 October 2002, which killed 202 people, including many Westerners.
Their group is also suspected of being behind a suicide bombing at the Marriott hotel in Jakarta in 2003, and a suicide bombing at the Australian embassy last September.
The suspected spiritual leader of JI, Abu Bakar Ba'asyir, issued a statement from prison on Tuesday condemning Saturday's attacks.
"I very much disagree with the bombings, whatever the reasons, in peaceful places including Bali, which definitely sacrificed innocent people," it said.
Abu Bakar Ba'asyir was sentenced to 30 months jail in March for conspiracy, after he was found guilty of giving his approval for the 2002 bomb attacks on Bali, which killed 202 people.
The three bombs on Saturday exploded in the tourist areas of Jimbaran and Kuta within moments of each other.
Most of those killed were Indonesian, but casualties are also believed to include people from Australia, Japan, South Korea and the US.
More than 100 people were wounded, 17 of them seriously.
BBC security correspondent Frank Gardner says Bali offers an attractive target for JI because it is full of Western tourists in a predominantly Muslim country.