GIZO, Solomon Islands — International aid workers rushed to dig latrines and set up water purifiers in the Solomon Islands tsunami disaster zone on Saturday in a frantic bid to stop the spread of disease.

Thousands of people in the Solomons' remote western province have been displaced by Monday's 8.1 magnitude earthquake and tsunami, and are now living in squalid camps in the forested hills above their ruined villages. Many are too frightened to return home.

Unhygienic conditions and a lack of clean water have contributed to a few isolated cases of diarrhea and dysentery in several camps around Gizo, one of islands hardest-hit by the disaster.

"The disease is a bit on a knife-edge," Stefan Knollmeyer, a relief coordinator with Australia's government aid body, AusAID, told The Associated Press. "There's a few cases of diarrhea at the moment, but without clean water" it may quickly spread.

His organization was working with New Zealand officials and the International Red Cross to dig latrines and set up water purification systems at dozens of refugee camps that have sprung up on islands and villages badly hit by the killer waves.

There were no official estimates of the number of cases of diarrhea and dysentery, but aid workers were optimistic that rudimentary sanitation measures — such as pit toilets, water purification tablets and soap — could contain the problem.

The United Nations said the death toll from Monday's disaster is at least 34 people. However, many villagers have been burying the dead as they find them, and some deaths may never be reported to officials.

Knollmeyer said the current estimates seem accurate based on AusAID's assessments so far.

"It may go up another 10. There are still reports of missing people, but it's not going to jump (much higher)," he told the AP from a command center in Gizo.

He said up to 7,000 people had been left homeless by the disaster — far fewer than originally feared. Earlier this week, the premier of the western province, Alex Lokopio, said as many as 40,000 of the region's 90,000 people may have lost their homes.

Meanwhile, two large boats docked in Gizo early Saturday carrying supplies and around two dozen troops from Australia and New Zealand, including at least five medics and half a dozen sanitation experts.

After days of delays caused by transport bottlenecks and government bureaucracy, more than 2,500 tarps and 1.2 tons of rice have been distributed to the camps around Gizo and some of the surrounding islands, according to Guy Redding of New Zealand's national aid organization.

Three large-scale water purifiers were due to be set up on Saturday, and around 50,000 water purification tablets have also been distributed, he said.