More than 150,000 people have been displaced in recent months by a vast military offensive, backed by heavy artillery, to drive the Liberation Tigers of Tamil Eelam (LTTE), known as the Tamil Tigers, out of the east.

As Sri Lanka's conflict enters a new and terrible phase, there are fears it will result in more civilian displacement and suffering.

Since 1983, Sri Lanka's government, representing the Sinhalese and Buddhist majority - around 75 per cent - has been battling the Tigers, who want a homeland in the north and east for the island's Tamil - and mainly Hindu - minority.

A ceasefire, brokered by Norway in 2002, promised an end to the violence, which has killed 70,000. But the election of a belligerent Sinhalese-nationalist government in late 2005, led by President Mahinda Rajapaksa, prompted a resumption of hostilities.

The government denies it, but with 5,000 dead in the past 18 months - compared with 200 in the preceding three years - the ceasefire is in tatters.

The present conflict - which Sri Lankan pundits have called 'Eelam four', as the fourth round in the struggle for a Tamil homeland, or Eelam - is taking place in two phases.

It began after a series of provocations that included an attack on the army headquarters in Colombo in April last year that left the army chief, Lieutenant-General Sarath Fonseka, badly wounded.

In the first phase, the army has largely succeeded in pushing the Tigers out of the east, but the region resembles a war zone. Many areas have been evacuated. About 25,000 soldiers swarm the area, and army camps and checkpoints are everywhere.

Around the town of Batticaloa is the sound of a steady dull thud of artillery fire. The army is still trying to bomb about 500 Tigers from their last jungle camps to the northwest and southwest of the town.

As the heavy troop presence attests, the government is fearful the Tigers will return and retake the land they lost.

'Wherever the people go, the LTTE will go, because the LTTE is the people,' said Perinbarajah Sellaiah, a displaced stonemason living at Sitandi camp in Batticaloa district.

Now, in a second major phase, government forces have turned their attention to the north, the Tigers' home and heartland.

Defence spokesman Kehilya Rambukwella denied there was a northern campaign. 'We just want to release people from the clutches of the LTTE,' he said.

But last Tuesday, the army announced it had bombed a Tiger training camp in the north. That followed a bloody mortar and artillery duel between government troops and Tigers in which both sides claimed to have killed dozens.

According to independent sources, the army has been making incursions across the northern front line for some weeks and has suffered heavy losses. To most observers this comes as no surprise.

'The battle in the north will be nothing like that in the east,' said Jehan Perera, executive director of the National Peace Council of Sri Lanka, a group working for reconciliation. 'It will be much harder.'

While the east has a population of Tamils, Muslims and Sinhalese, the north, which the Tigers already run like an independent state with its own tax system and police force, is almost entirely Tamil. Here support for the Tigers is strong.

Another factor in the army's eastern successes was the 2004 defection of the Tigers' regional commander, Vinayagamoorthy Muralitharan, known as 'Colonel Karuna'.

Karuna, as his splinter group is known, has since launched a series of attacks on Tiger bases.

Despite these apparent setbacks, the Tigers have struck back. In two attacks in March and April, their fledgling air force - with lightweight Czech planes smuggled into the country in parts and then rebuilt - bombed an air force base and oil facilities in Colombo, exposing serious weaknesses in Sri Lanka's defences.

On May 24, the Tigers launched an audacious raid on a naval base on the northern Jaffna peninsula - the only part of the north controlled by government forces - killing dozens.

Bomb explosions in Colombo followed, including one that targeted an army truck but killed six civilians.

Western governments have long condemned the Tigers' terrorism and their habit of recruiting child soldiers. In some northeast areas, they have demanded up to two child fighters from each family.

But recently, foreign governments have been horrified by reports of atrocities carried out by paramilitaries linked to the government. Last month, Britain withdrew some debt relief to Sri Lanka, citing the government's poor human rights record.

Early last month, Richard Boucher, the US assistant secretary of state for south and central Asian affairs, visiting Sri Lanka, said Washington was concerned by abductions and killings blamed on both sides - and said the US was withholding aid.

Human Rights Watch says that the Karuna group has recruited child soldiers and abducted scores of civilians with the approval of police and military.

In a camp for the displaced in Sitandi, in Batticaloa district, Radikhela Vanarasa describes the day Karuna cadres came for her father. He was working as a cook in a Tamil Tiger camp to prevent the rebels forcibly enlisting his young sons.

'The Karuna men came in the evening,' said the 21-year-old, her eyes fixed on the ground. 'They said, 'You are working for the LTTE' and chopped off his hands. They beat him, tortured him and removed his intestines.'

Ms Vanarasa's husband was forcibly recruited by Karuna's fighters weeks later, she added.

In the same camp, Belautham Yogarasa told of how her 35-year-old son had been taken away by armed, plain-clothes men one night in February and bundled into an unmarked white van. She has not seen him since.

'He had no links with any group,' she says. 'We don't know where he's gone or why they abducted him.'

Some of the worst human rights abuses have taken place in Jaffna, where more than 300 civilians have been murdered in the past 18 months. Many suspect responsibility lies with a paramilitary force with close ties to the military intelligence agency.

M.V. Kaanumylnathan, editor of the popular Sinhalese newspaper Uthaya, lost two of his journalists when armed masked men burst into his office on the evening of Press Freedom Day and opened fire.

Seven more survived by hiding in the toilet, says Mr Kaanumylnathan, as he sits against an office wall still riddled with bullet holes. He walks with a stick after a vehicle mowed him down in the summer of 2001 'with the purpose of killing me'.

'There are no human rights in Jaffna,' said A.K. Sivasubramaniam, co-ordinator of Sarvodaya, a charity in Jaffna. 'People are even scared to talk about how there are no human rights.'

Last August, the A9, the only road that links Jaffna to the rest of Sri Lanka, was closed. Since then the price of food and medical supplies, transportable only by sea and air, have soared, compounding the suffering of ordinary people.

Earlier this year, a 400-gram packet of a popular brand of milk powder sold in Jaffna for 350 rupees (HK$25). Elsewhere on the island, it cost 163 rupees.

A shortage of building materials means little is being built and there is practically no investment.

'Everything here is at a standstill,' says Bishop Thomas Savundaranayagam, head of the Catholic Church in Jaffna. 'It's like living in an open prison, and there is great anxiety about what will happen next.'

Recognising, perhaps, that the army is facing an unwinnable war in the north, the government seems to have toned down its gung-ho rhetoric.

After last week's bloody fighting, General Fonseka said the time had come for a new ceasefire.

But few are hopeful of a new round of peace talks any time soon. For one thing, the government is being held to the promise it made when it came to power - to crush the Tigers militarily - by hardline Sinhalese nationalists.

Among them is a party of Buddhist monks, Jathika Hela Urumaya, or the National Heritage Party, which joined the coalition government in January, pushing its majority of one up to nine.

The party rejects all suggestions that the Tamils should have even a measure of autonomy in the north - a condition many believe is necessary for lasting peace - and are cheering on the military campaign.

'Day by day we are weakening the LTTE militarily,' said the Venerable Athuraliye Rathana, the monk who leads the party in Parliament. 'Talk can come later.'

Many moderate Sinhalese are influenced by this kind of thinking. A recent poll by the Centre for Policy Alternatives, a Colombo think-tank, found nearly 60 per cent of the Sinhalese wanted a military solution.

'We're all sick of war, and I feel so sorry for the Tamils who are suffering,' said a Sinhalese taxi driver in Colombo whose earnings have fallen with the tourist numbers.

'But giving the power in the north would not be good. They might try to extend their power. I'm afraid this war is going to go on and on.'