At least one Australian is among 19 people killed in explosions in the popular Indonesian resort island of Bali, Foreign Affairs Minister Alexander Downer said.
Up to four explosions rocked tourist areas of Kuta and Jimbaran Beach, wounding 51 people, including three Australians.
One hospital official said at least 35 wounded foreigners were taken to the main hospital on Bali.
Mr Downer says he is finding it hard to get detailed information.
'There are reports that there could be between 30 and 40 injured and some reports are suggesting that there are nine or so dead but these numbers are very early and they could change significantly,' he said.
'We know from experience the numbers unfortunately could turn out to be a good deal higher than that.'
Daniel Martin, a tourist in Bali, says there was chaos after the blast in Kuta Square.
'There was thick smoke for a few minutes afterwards but there didn't seem to be any fire,' he said.
'People were clambering onto the roof of the restaurant. It's about a three storey building so people were climbing out and screaming and jumping down to the street.
'It was pretty harrowing stuff.'
Phonelines between Bali and other parts of the country were overloaded, as people struggled to contact friends and relatives in the area.
Peter Holden of Gosford on the central coast of New South Wales says he received an SMS message from his daughter Donna, who lives in Bali, telling him about the explosions.
Mr Holden says his daughter has reported several fatalities.
'There have been at least two bombs gone off in Jimbaran in restaurants and those kind of restaurants are restaurants populated by tourists in the main,' Mr Holden said.
'And then a more recent report just a moment ago that there's also reports of another bomb in Kuta Square. That's a pretty busy tourist area,' he said.
The blasts come almost exactly three years since two nightclubs were bombed in Bali's famous Kuta Beach in October 2002, killing 202 people, including 88 Australians.
Deadly blasts rip through Bali again
Explosions rocked�the Indonesian tourist island of Bali last night, leaving at least 23 people dead and dozens wounded.
Witnesses said they saw body parts, including a severed head and a leg, and hospitals filled with injured.
Many foreigners were�among those killed. The Foreign Affairs Minister, Alexander Downer, said at least one Australian
was confirmed dead.
The blasts at Jimbaran beach and a bustling outdoor shopping centre in downtown Kuta "were clearly the work of terrorists'',
Police Major General Ansyaad Mbai, a top Indonesian anti-terrorism official, told the Associated Press.
Komang, a receptionist at the Graha Asih Hospital, close to Jimbaran Bay, said there were at least eight people in the morgue and that doctors were treating at least 13 wounded. "It's a horrible scene,'' she said. "Some people have had their heads blown off.''
The bombs went off almost simultaneously at�about 7.30pm local time (9.30pm Sydney time).
The blasts hit two restaurants that were packed with foreign and Indonesian diners.
Wayan Kresna said he witnessed the first bomb at a seafood restaurant on Jimbaran beach. He counted at least two dead and said many others were taken to hospital.
Australian agencies to consider Bali response
This attack comes almost three years to the day after terrorists killed 202 people, including 88 Australians, in a similar attack on two Kuta bars.
Indonesian President Susilo Bambang Yudhoyono has condemned the blasts as a criminal act.
Anyone who has relatives or friends in Bali is advised to try to contact them directly before calling the DFAT hotline on 1800 002 214.
Here we go again. Reported fatalities have risen from nil to 23 over the last hour.