HEALTH officials are going door-to-door with mosquito-killing spray guns to head off a malaria threat that one expert said could kill 100,000 more people around the tsunami zone.

Relief workers, meanwhile, warned that new rules requiring them to travel with armed escorts in Indonesia's Aceh province could cause bottlenecks in aid delivery.

"We discourage such actions because it blurs the distinction between humanitarian and military efforts," said Eileen Burke of Save the Children.

All across disaster-hit southern Asia, fresh challenges confronted the massive aid effort.

In India's remote Andaman islands, Red Cross officials accused government workers of stealing their relief materials. In Sri Lanka, Unicef said Tamil Tiger rebels were recruiting tsunami-affected children.

In Aceh, the threat of cholera and dysentery outbreaks is diminishing because clean water is getting to tsunami survivors, but the danger of malaria and dengue fever epidemics is increasing, says Richard Allan, director of the Mentor Initiative, a public health group that fights malaria epidemics.

The death toll from the earthquake and tsunami has topped 157,000 across 11 countries - with two-thirds of the casualties in Aceh.