BANDA ACEH, Indonesia -- Indonesia warned aid workers yesterday that separatist rebels have taken shelter in camps for survivors, and a burst of violence hit Sri Lanka, signaling a potential resurgence of long-simmering rebellions in both countries that could hamper help for victims of the tsunami disaster.
Tropical downpours complicated relief efforts already slowed by impassable roads and destroyed bridges. Tens of thousands of survivors living in little more than tents out in the drenching rain underscored the need to build permanent shelters.
Decades-old conflicts in Indonesia and Sri Lanka lay dormant in the first two weeks after the magnitude-9 earthquake and tsunami struck, killing more than 150,000 people in Asia and Africa. But now they threaten to re-ignite as aid workers poured into the region with emergency assistance, some traveling to areas where outsiders are almost never allowed.
The workers say they are being cautious but won't let concerns about the rebellions slow the flow of aid.
''We don't believe that aid workers are targets," said Joel Boutroue, head of the UN relief effort in Indonesia's troubled Aceh Province.
Ethnic tensions overshadowed UN Secretary-General Kofi Annan's tour of devastated areas in Sri Lanka. Hundreds protested in Sri Lanka's Tamil-dominated north after he acceded to a government request not to visit areas under rebel control.
''I'm hoping to come back and be able to visit all areas of the country, not only those repaired, but also to celebrate peace," Annan said before heading to the Maldives. ''The UN is not here to take sides."
A rare burst of violence between Christians and Hindus in eastern Sri Lanka, where a massive aid effort is underway, revived security fears for relief workers there. At least three people were killed and 37 injured.
The Indonesian government warning offered no details about the infiltration into survivor camps, but was issued hours after police in the provincial capital, Banda Aceh, blamed separatists for nighttime gunfire close to the main UN compound in town.
Local military spokesman Ahmad Yani Basuki told the state-run Antara news agency that volunteers must understand that Aceh ''is not like other regions in Indonesia. This is still a conflict-torn region," he said.
Indonesian authorities blamed separatist rebels for the shooting, near the house of a provincial police official. But the government routinely blames the rebels for violence -- even without evidence.
The rebels have waged a separatist war in Aceh for nearly three decades in a conflict that has killed thousands. An unofficial truce settled in after the Dec. 26 disaster, but recent skirmishes have prompted Indonesia's military to step up patrols for the guerrillas.
Security concerns have also been heightened by the appearance of Laskar Mujahidin, an extremist group with alleged links to Al Qaeda. The group has set up an aid camp, but says it only wants to help and won't target foreigners.
Still, the aid effort continued unabated, with the World Food Program sending 170 staff members.
Other agencies have similar numbers. The US military, with hundreds of personnel on ships near Sumatra and in Sri Lanka, said aid workers must be on guard in restive areas.
''Security is a constant planning factor in all that we do," said Major Nelson Chang, US Army aid coordinator.
Aid officials said they may have to feed as many as 2 million survivors a day for six months.