KALMUNAI, SRI LANKA -- Here on the eastern coast of Sri Lanka, businesses were already suffering the devastation caused by last year's tsunamis. But in the past few weeks, they have discovered a new, more menacing sort of visitor.

"The men from the Tigers came in last week. They were wearing uniforms, and they sat down with me and told me to make a donation of 3.5-million rupees [about $40,000], or else something bad would happen to my guests," the Tamil-speaking owner of a coastal hotel, used by aid workers in the tsunami-relief effort, said in a recent interview.

He was indignant. "They say they are my people, but they are taxing me more than half the money I earn in a year."

His visitors, he said, were from the Liberation Tigers of Tamil Eelam, known as the Tamil Tigers.

The Tamil Tigers have been fighting a bloody military and terrorist campaign since 1983 for an independent country for those speaking Sri Lanka's minority Tamil language. That conflict has killed at least 60,000 people but has lain dormant since a fragile ceasefire was negotiated in 2002.

The hotel owner was one of several Tamil businessmen who said in interviews that they have been subjected to extortion efforts by the Tigers, often after they have received money related to post-tsunami reconstruction work.

None of them had experienced extortion attempts previously from the LTTE, which reportedly gets the majority of its funds through voluntary donations from Tamils living in wealthier countries such as Canada.

The reports were supported by officials from major aid agencies working in the region, and from United Nations officials, who said that contractors hired in the tsunami-rebuilding effort have been harassed by LTTE representatives during the past month.

"This is a very troublesome new problem that we have been hearing about from the businesses that supply food to us -- the LTTE demanding money, which is a very recent development," said Angelo Loganathan, the administrator of the UN's World Food Program in the Ampara district of eastern Sri Lanka.

"The LTTE have never interfered with us directly, they leave the UN alone, but it is very alarming that they are now bothering our suppliers."

These tales echo reports this week in Canada that members of the Canadian Tamil population have been told to make a $2,500 donation to the LTTE if they wish to be admitted across military checkpoints into Tamil-controlled provinces to visit their relatives.

The reports are being investigated by Ottawa.

On Nov. 23, Australian police raided Tiger offices in Melbourne in response to similar reports of extortion.

Extortion of Tamils is a new tactic for the LTTE, veteran observers say, and it may signal a new urgency in the movement's fundraising, in part because its navy was devastated in the tsunami and because the Tigers appear to be preparing for an all-out war.

"They certainly have done fundraising in this region before, but this is the first time we have seen them squeezing businesses in their own community," said an official with a British aid agency that has been working here for most of the past decade.

The southeast coast of Sri Lanka, whose population is an uneasy mix of Tamils and Muslims, is currently awash in international aid money because its heavily populated fishing-and-farming coastline was devastated by the Dec. 26, 2004, waves.

Some aid workers said they believe the Tigers are trying to take advantage of this for fundraising purposes.

But they also pointed out that the Tigers have not been interfering with the flow of aid money and supplies to victims. While there were incidents last December of the LTTE officers insisting on seizing aid shipments and distributing them themselves, officials from several major agencies said yesterday that the past year has been almost entirely free from political interference with aid.

"All of our shipments have made it across the LTTE checkpoints without being touched, and they have allowed us to have complete control over the distribution of aid," said a senior official with the International Committee of the Red Cross.

"If they're trying to get access to aid money, they are not doing it directly."

Others suggested that the businesses in tsunami-hit regions are being hit because they are among the few Tamil-run firms in the island's east and north that are making significant sums of money.

The money-raising efforts have taken place as outright violence erupted last month in the north and the east of Sri Lanka, killing 27 people in grenade attacks, shootings and assassinations in which Muslims have been repeatedly killed and wounded, attributed to the LTTE.

Sri Lanka is on its highest security alert, and heavily armed soldiers have appeared on most street corners for the first time in years.

Here in the east, armoured vehicles patrol the streets and dozens of soldiers, often hidden behind sandbank emplacements, guard mosques and Islamic schools and patrol the beaches and narrow streets of the poor neighbourhoods.

Three years of peace were shattered with a grenade thrown into a mosque on Nov. 18, one day after Sri Lankans elected a new president, Mahinda Rajapakse.

The blast killed seven people and was followed by a string of shootings and grenade-throwings that have killed four more people in the poor towns along the coastal road in the east.

A nation in conflict

Since 1983, the island of Sri Lanka has been fractured by a civil war between its two major linguistic groups, Sinhalese and Tamil. The conflict, which has killed between 60,000 and 100,000 people, has been characterized by terrorism, suicide bombings and the use of child soldiers. While a ceasefire was declared in 2002 with the help of international monitors, the past few weeks have seen a return of violence that has led some observers to fear that all-out war might return.

The Sinhalese-led government: The largest group of Sri Lankans speak Sinhalese, and are mostly Buddhist. When the island was part of the British empire, the Sinhalese were second-class citizens, but upon independence in the 1950s they took control of the government and for a while denied jobs and status to the Tamil-speaking minority, who had previously been the island's elite.

The Tamil Tigers: Tamil speakers are mainly Hindu (but also include many Christians and Muslims). Their civil-rights movement, provoked by acts of Buddhist terrorism against Tamils in the late 1950s, was seized by extremists and turned into an armed independence movement.

The Liberation Tigers of Tamil Eelam (the LTTE, popularly known as the Tamil Tigers) declared the island's northern and eastern regions an independent state known as Eelam. Tiger soldiers currently control only the northern province, which is run as an austere military dictatorship in which Tiger founder Prabhakaran is worshipped in a personality cult. The northern city of Jaffna, which the LTTE claims, is now under heavily fortified Sinhalese occupation. During the past week, two remote-controlled land mine attacks have killed 14 Sinhalese soldiers in Jaffna.

The Muslims: Although they speak Tamil, Muslims have not generally been willing to join the LTTE's cause. For this resistance, they have been punished severely. Violent attacks on Muslims began in 1991, focused on the heavily Muslim regions of Sri Lanka's southeastern coast. In the 1990s, all Muslims were expelled from their homes in Jaffna in an act that has been described as ethnic cleansing. Because much of the fishing in Sri Lanka is done by Muslims, they were inordinately victimized in the Boxing Day tsunami of 2004. In recent weeks, attacks on Muslims, often housed in tsunami shelters, have escalated across the region.