Australian Mercedes Corby said she had seen Australians with shrapnel wounds, broken bones, horrific burns and eye wounds after the latest Bali bombings.

Mercedes Corby is the sister of Australian Schapelle Corby who is serving 20 years in a Bali jail after being convicted of drug trafficking.

Ms Corby spent all night helping people injured at Kuta, near the Bali capital of Denpasar, after at least one bomb went off. Two simultaneous bombs struck restaurants along Jimbaran beach in Bali.

Australian Foreign Minister Alexander Downer said at least 25 people appeared to have been killed, including possibly three Australians, in the blasts at Kuta and Jimbaran village, but media reports indicate the figure could be higher.

Mr Downer said 17 Australians hade been injured, three seriously.

Ms Corby was reported to have nursed one badly injured woman as she died in her arms.

"(There were) a lot of shrapnel wounds, broken bones, face (and) skin blown away, leg wounds, shock," she told the Nine Network.

"At the Raj (Hotel) there wasn't a lot of burns but mainly shrapnel (wounds)."

Ms Corby, who lives in Bali, said she had spoken with a few Australians in Denpasar hospital.

"They were mainly shrapnel wounds, broken bones. One lady has burns to her eyes and deafness from the blast," she said.

Ms Corby praised the response of the Indonesian authorities.

"They did a really good job," she said.

"In the hospital, at first there were not enough beds (and there were) people on the floor.

"But they worked hard and they got it together really quickly."

She lamented the effect on the people of the tourism haven to the north-east of Australia.

"I really feel for the Balinese people. It's so sad. It's really going to hurt them," she said.

"They're so caring. They are even coming up and saying to Australians and to us `sorry, are you OK, anything we can do?' ... the way the locals were in there helping, trying to find victims, putting everyone in the ambulances."