Tensions are rising between militant Islamic groups working in tsunami-struck Aceh and local residents as the outsiders seek to force hardline views on the traumatised local community.

Tempers flared outside a mosque in the capital Banda Aceh where hundreds of supporters of the Islamic Defenders Front, or FPI, have set up tents in a cemetery across the road as they help in Aceh's cleanup and guard local mosques against "unwanted foreign influences".

When a local driver employed by an Australian newspaper was interrogated outside the two-storey mosque about who he was working for, a man who identified himself as a "FPI mujahidin" spat on the ground and accused him of "working for the enemy".

"At the least the Australians are helping us," the outraged driver named Amir shot back. "What would be better? Maybe going around bombing more hotels and killing more people like you people want to. How is that supposed to help us?" he screamed.

The FPI is just one of a number of radical Islamic groups, some with links to terrorism, which are flocking to Aceh to fill a power vacuum created by the deaths of thousands of security forces and officials in the recent earthquake and tsunami tragedy.

Fuelling fears religious instability could worsen the already long-running separatist conflict in the province, the FPI and the Indonesian Mujahidin Council (MMI) of suspected terrorist leader Abu Bakar Bashir are now in the province.

Others include Laskar and Hizbut Tahrir Indonesia, which seek to strengthen Islamic sharia law in Aceh to a strict Middle East-style version which would include stoning for adultery and cutting off the hands of thieves.

FPI is best known for conducting "sweeping raids" to smash up bars and nightclubs they deem un-Islamic.

The group now has around 3,000 members in Aceh, helping the army to bury bodies and guard mosques as thousands of foreign military and civilian humanitarian workers work on the cleanup of Indonesia's only province to have adopted Islamic sharia law.

But while most Acehnese are religiously conservative, sharia's implementation was more the result of a political deal between Aceh's clerics and the provincial government rather than strong support among the people.

Adding to tensions is the fierce dislike many Acehnese have for Javanese Indonesians.

At the same mosque last week, local residents arrived in force to demand FPI members stop their two-hour-long morning Koran readings being broadcast on loudspeakers along with the usual call to prayer.

"Do you think you are still in Jakarta," one woman shouted when FPI members tried to bar a Muslim westerner from entering evening prayer. "Don't you dare come here and try to tell the Aceh people how to run their own mosque."

The locals also demanded the FPI allow their more moderate local cleric back into the mosque after he quit the building in disgust several weeks ago when the outsiders arrived. An FPI spokesman said the group was in Aceh only to protect its "Muslim brothers".

But local people accused MMI and FPI of being interested in the hundreds of millions of dollars in aid money pouring into Aceh. "They are insincere in their concern for Aceh. They do not help like the foreigners do," one woman named Dede said. "We need Australia and America and Germany to stay as long as they can, because we need them to rebuild Aceh."

Indonesia's government has set a three-month exit date for foreign military forces, although it said the March 26 deadline was flexible. But is still unclear whether the government will demand the departure of civilian aid workers from the politically-sensitive province where separatist rebels have been waging a long-running battle for independence.

In Jakarta, Indonesia's health ministry said the number of people dead and missing after the earthquake and tsunami had risen by 913 to 241,687. It said the number of confirmed dead and buried was 113,913 while the number of people missing feared dead remained at 127,774.

Officials say the missing will only be confirmed dead after one year. Different government agencies have given conflicting statistics on the casualty figure for the Indian Ocean disaster.