The death toll from a tsunami that struck remote islands off western Indonesia rose to at least 430 on Thursday, and it's likely to rise higher as rescuers continue to search the area.

Indonesia has been hit hard by natural disasters in recent days. The Mount Merapi volcano also erupted this week, killing 33 people, and continues to spew ash and smoke, threatening further destruction.

Though 1,300 kilometres apart, the two catastrophes struck within 24 hours of each other. Mount Merapi lies in central Java, while the tsunami struck the remote western Mentawai islands, lying between Sumatra and the Indian Ocean.

Canada's Minister of Foreign Affairs Lawrence Cannon offered the nation's condolences on Wednesday, following the destruction.

"On behalf of all Canadians, I offer our deepest sympathy to the families and friends of those killed, and wish a quick recovery to the injured. Canada stands ready to provide support to the people of Indonesia if requested," Cannon said in a statement.

He said there are no reports of Canadians being killed or injured in the disasters.

Search and rescue crews working in the tsunami-hit region said Thursday they expect the death toll to climb even higher.

"They believe many, many of the bodies were swept to sea," Harmensyah, head of the West Sumatra provincial disaster management centre, told The Associated Press.

Crews were able to resume searching Thursday after being kept away by days of high waves and storm weather. They encountered beaches littered with swollen corpses, Harmensyah said.

Where villages once stood there were flattened houses and massive flood plains.

"Not even the foundations of houses are standing. All of them are gone," said Harmensyah, who uses only a single name.

According to reports, a multibillion-dollar warning system that was brought in the aftermath of the 2004 earthquake and tsunami, wasn't working. Officials said it wasn't being maintained properly and broke down.

Many survivors have crowded into an impromptu medical centre in Sikakap on Pagai Utara, waiting for treatment of their injuries and looking for a dry place to sleep.

Huge swaths of land were underwater and houses lay crumpled with tires and slabs of concrete piled on the surrounding sand.

Harmensyah said the teams were losing hope of finding those missing since the wall of water, created by a 7.8-magnitude earthquake, crashed into the islands on Monday.

"They believe many, many of the bodies were swept to sea," he said.

Meanwhile Mount Merapi, which first erupted on Tuesday, killing 33 and injuring 17, began erupting again on Thursday.

It is unclear whether the recent activity is a sign that another major blast can be expected.

Most residents of the area have been evacuated. The hardest-hit villages of Kinahrejo, Ngrangkah and Kaliadem have been emptied, with residents piling into refugee camps.

Officials even moved livestock down the mountain to discourage residents from trying to return to their homes.