Police said the first blast on Saturday tore through the Raja restaurant in the shopping district of Kuta, the scene of the 2002 bombings which left 202 people dead, mostly foreign tourists.
Minutes later, two further explosions ripped through a pair of beachfront restaurants 30km away in the picturesque fishing village of Jimbaran.
"The explosion in Kuta square took place at 1930 (1130 GMT). At 1940 was the first blast in Jimbaran and at 1941, the second blast," said Bali police spokesman A S Reniban.
The confirmed toll stood at 25, a hospital official said, correcting an earlier figure of 32. More than 100 were injured.
Human bombers carried out the attacks, said a top anti-terrorist official.
Police: Jimbaran blasts more
powerful than Kuta explosion
Major-General Ansyaad Mbai said the three attackers went into the packed restaurants on Saturday evening wearing explosive vests. The remains of their bodies were found at the scenes, he said.
"I have seen them. All that is left is their head and feet," he said. "By the evidence we can conclude the bombers were carrying the explosives around their waists."
He also said two Malaysian fugitives were suspected of masterminding the strikes.
Malaysians Azahari bin Husin and Noordin Mohamed Top have been on Indonesia's most wanted lists since the 2002 Bali attacks.
The two - alleged to be key members of the al-Qaida-linked Jemaah Islamiyah group - were accused of orchestrating those blasts and two others in the Indonesian capital in 2003 and 2004. Those attacks also involved human bombers.
"The modus operandi of Saturday's attacks is the same as the earlier ones," said Mbai. "We suspect [Husin and Top] were behind this."
A bulletin board at the hospital detailing casualties said that the dead included one Japanese and two Australians.
Three other Caucasians - one man and two women - had yet to be identified.
Indonesian President Susilo Bambang Yudhoyono immediately
condemned the latest bombings and vowed to hunt down the perpetrators. "These are clearly terrorist attacks because the
targets were random and public places," he said.
"The blast there (in Jimbaran) is much stronger because there we found a head that was separated some 50 metres from its body"
senior police commissioner
At the scene of the Kuta bomb, bodies lay covered by bloodied blankets as police moved among crowds of onlookers using torches to pick their way through the gutted interior of the restaurant.
British tourist Daniel Martin told the BBC he was standing in a building next to the restaurant in Kuta when a "tremendous" explosion erupted.
"It was just sheer chaos with no one really taking control," Martin said, adding that "there were no police or anyone else around for a good while. It was everyone pitching in to help the wounded".
"There were people lying in the street with serious wounds, blood pouring into the street ... I was afraid to go into the actual restaurant for fear of what I might see in there."
Senior Police Commissioner Dewa Parsana told journalists in Kuta that the blast there had not been as powerful as the explosions in Jimbaran.
"The blast there (in Jimbaran) is much stronger because there we found a head that was separated some 50 metres from its body," Parsana said.
Judging from the timing and the maximum impact of the blasts, he said the bombings were "very well planned".
Bashir is serving a two-year
sentence for the 2002 attacks
Australia, which lost 88 citizens in the 2002 attacks, confirmed that a 16-year-old Australian teenager was killed and at least 17 other citizens were injured.
Susilo had called in late August for tighter security in the world's most populous Muslim nation during September and October, saying these appeared to be favoured months for terrorist acts.
In the Bali blast case, three have been sentenced to death and two others are serving life sentences.
A spokesman for Indonesian cleric Abu Bakr Bashir said the imprisoned had nothing to do with Saturday's bombings.
Bashir, 67, is serving a two-year sentence for conspiracy in the 2002 attacks. Foreign governments have long maintained he is Jemaah Islamiyah's spiritual leader.
Spokesman Fauzan Al Anshari said: "That is an old tune. No Muslim would carry out those bombings."
He said Saturday's attacks were part of a "grand design" to discredit Bashir, who is due to be released next year. "We are very worried that this will be linked to Bashir," he said.