The blasts killed 22 and wounded 138, and police have launched a nationwide hunt for the masterminds, which a senior officer said on Wednesday was focussing on Bali and the Indonesian capital, Jakarta.
Attention has centred on the Jemaah Islamiah network or an offshoot of it. In particular, Malaysia's Azahari bin Husin and Noordin Top - believed to be somewhere in the vast country -are being sought.
The two are senior figures in Jemaah Islamiah, blamed for attacks on Western-related targets in Indonesia, including nightclub bombings in Bali three years ago that killed 202.
Police say they have questioned 39 people about the bombings in which the attackers killed themselves. Among those questioned were two non-Balinese interrogated on the island for suspected involvement.
However, while police say they are making progress, no one has been formally arrested or charged.
"There's nothing new, not yet," deputy national police spokesman Soenarko Artanto told reporters on Wednesday.
"The perpetrators should be brought here. I will kill them myself. We don't want anything like that to happen again"
Ketut Noren, Jimbaran resident
Bali's Hindus, the majority population there, were observing the major religious holiday of Galungan on Wednesday, while for Muslims the day began the fasting month of Ramadan.
Hindus traditionally conduct prayers throughout the day, which celebrates the victory of good over evil.
Dozens of Hindu residents stopped by blast sites at two Jimbaran beach restaurants on their way to temples. Women wore traditional long kebaya dresses, while men were in white scarves and shirts and colourful sarongs.
Ketut Arini, 20, a waitress at Menaga cafe, one of the bomb targets, splashed water and placed offerings of incense and fruit in every corner of the cafe building. "I look for blessings so that the spirits are gone," she said.
Blasts ripped through the two Jimbaran restaurants and a cafe in Kuta Beach almost simultaneously on Saturday night as they were packed with diners.
Police say there were three bombers. Media have given wide coverage to amateur video of one suspect, seconds before a blast, and photos of severed heads believed to be those of the trio.
Police say the bombs appeared to have been made cheaply using TNT, ball bearings, bolts and a detonator packed into plastic containers and may have been detonated by mobile phone.
Over two dozen have been jailed
in the 2002 Bali bombings
Jakarta's police chief said members of the cell responsible could be hiding in the capital, a sprawling city of 12 million.
"After Bali, that is the biggest possibility," Firman Gani said, adding Jakarta police were on high alert for more attacks.
In Banten province on Java island, police were checking on five men linked to a person involved in the 2002 Bali blasts.
"When we heard the news of the Bali bombing, the Banten police chief instructed us to monitor the five," said Aridono, of the local police research department. He gave only one name.
Banten is 50km west of Jakarta, itself the target of deadly bombings in the past two years targeting a luxury hotel and the Australian embassy.
President Susilo Bambang Yudhoyono said on Wednesday that he had asked the country's military to help in the anti-terror fight.
Bali is a majority-Hindu enclave in the world's most populous Muslim nation. Although most Indonesian Muslims are moderates, some are showing signs of growing militancy.
In New York, Indonesia's UN envoy told the Security Council the blasts would not deter the world's fourth-most-populous nation from seeking an open and democratic society.
At least 22 people were killed by
the bomb blasts on Bali island
The government intended to press on with efforts "to promote tolerance and peaceful coexistence through empowering the moderates of our society", Ambassador Rezlan Ishar Jenie said.
But on Bali, where the lifeblood tourism industry is at risk, some seemed more interested in revenge than words of tolerance.
"The perpetrators should be brought here. I will kill them myself. We don't want anything like that to happen again. No more bad spirits coming to the island again," Jimbaran resident Ketut Noren, 45, told reporters after praying at a nearby temple.