The Sri Lankan government has been accused of launching a campaign of "ethnic cleansing" following its victory over the Tamil Tigers in the country's 26 year civil war.

Aid officials, human rights campaigners and politicians claim Tamils have been driven out of areas in the north-east of the country by killings and kidnappings carried out by pro-government militias.

They say the government has simultaneously encouraged members of the Sinhalese majority in the south to relocate to the vacated villages.One foreign charity worker told the Daily Telegraph the number of Tamils disappearing in and around Trincomalee, 50 miles south of the final conflict zone in Mullaitivu, had been increasing in the last three months.

He claimed to have known 15 of the disappeared, three of whom had been found dead. He said all three bodies showed signs of torture, while two were found with their hands tied behind their backs and single bullet wounds in their heads.

Another aid worker said the killings were part of a strategy to drive out the Tamils.

"Eastern province is vulnerable, there's cleansing by the Sinhalese. There will be more problems with land grabbing. The demography changes and the Tamils who are the majority will soon become a minority," he said.

He claimed many villagers had moved out after the army declared their land to be part of a 'high security zone' and Sinhalese had been given incentives to move in to provide support services to new military bases.

Many Tamils sold their homes and land at below-market prices after members of their families had been killed or had disappeared, he said.

One western human rights advocate said Tamils in and around Trincomalee were terrified because they believed the police were either complicit in, or indifferent to, the numbers disappearing or found dead. "There's no investigation. It's a climate of terror and impunity," he said.

A local campaigner for the families of the disappeared said the killings were speeding the flight of Tamils from the area. "When there's a killing other Tamils move out. Who goes to the Sinhalese police? You either live under threat or you move out," he said.

He said much of the "ethnic cleansing" was being done in the name of economic development in which Tamil villagers were being moved out to make way for new roads, power plants and irrigation schemes, while Sinhalese workers were being drafted in with incentives including free land and housing.

"Thousands of Sinhalese are coming in, getting government land and government assistance from the south. It's causing huge tensions," he said.

He and others fear this model will now be applied to the north where the final army onslaught to defeat the Tamil Tigers left 95 per cent of the buildings demolished or heavily damaged.

Since the victory earlier this month, President Mahinda Rajapaksa's government has been under pressure to 'win the peace' with a generous devolution package for Tamils in the north.

Ministers have said they want to break the identification of the Tamils with the northern and eastern provinces and integrate them into the Sinhalese majority population throughout the country.

In Colombo, billboard posters have contrasted the "divided" pre-victory Sri Lanka, with the Tamil north and east shaded red, and the "united" post-war island.

Ministers have said billions of dollars will be needed to rebuild the area's roads, buildings, schools, hospitals and water, electricity and communications infrastructure. Community leaders and Tamil politicians fear this will mean a further influx of Sinhalese.

R. Sampanthan, the parliamentary leader of the Tamil National Alliance and an MP for Trincomalee said he shared these fears. A new road being constructed from Serubilla, a Sinhalese village in Trincomalee district to Polonaruwa, a Tamil village, was under construction and Sinhalese families were being settled on either side of the road as it snakes further north-east.

"It's ethnic cleansing, and we're concerned that this is what they will also do in the north," he said.