COLOMBO Western diplomats pushed for a ceasefire in Sri Lanka. The UN expressed grave concern over civilian deaths.

But with no threats of sanctions or other meaningful punishments facing Sri Lanka, the government has simply pushed ahead with its battle to destroy the Tamil Tiger rebels in what might be the bloodiest war on the planet.

“They've shown that they don't care what the UN says, they don't care what the White House says - they'll just do as they please,” said Zahir Janmohamed, of Amnesty International.

Since January, the military has wracked up impressive victories, forcing the heavily armed rebels out of the shadow state they controlled in the north, surrounding them in a tiny coastal strip and nearly ending their quarter-century war for a separate homeland for minority Tamils.

But it has come at a heavy price.

UN figures show 7,000 ethnic Tamil civilians were killed between Jan 20 and May 7. Health officials in the war zone estimate at least another 1,000 have been killed since then. Hundreds, if not thousands, of combatants have also been reportedly killed, though neither side releases casualty figures.

Those deaths exceed the casualty tolls this year for the conflicts in Iraq, Afghanistan, Pakistan and Gaza combined. Associated Press counts show fewer than 1,500 Iraqis and 66 US soldiers were killed in Iraq this year, about 1,800 militants, civilians and soldiers were killed in Afghanistan and fewer than 1,600 were killed in Pakistan. Israel's incursion into Gaza killed between 1,100 and 1,450 people, based on conflicting Israeli and Palestinian figures.

The civilians also face a severe food shortage and what the Red Cross called “an unimaginable humanitarian catastrophe.”

The US has condemned the rising death toll. President Barack Obama insisted the Sri Lankan government stop its “indiscriminate shelling.”

Britain and France failed to broker a humanitarian truce. UN Secretary-General Ban Ki-moon warned both sides “the world is watching” and has sent his chief of staff here to stop the bloodshed.

But aside from threats by Britain and the US to temporarily delay - not block - a badly needed $1.9 billion IMF loan, Sri Lanka has faced no repercussions for pressing on with the offensive.

Partly, it's because of the viciousness of its enemy.

The Tamil Tigers have been branded terrorists responsible for hundreds of suicide attacks and assassinations and accused of holding an estimated 50,000 civilians in the war zone as human shields, shooting those who try to flee. Diplomats say there is little pressure they can apply to the rebels, because they are already outlawed and blacklisted internationally.

Sri Lanka says the war is part of the global fight against terror, and few governments seem interested in punishing a country they believe is justifiably trying to crush a stubborn insurgency.

“The lingering sympathy for Sri Lanka as a state battling a ruthless terrorist organisation has muted” some of the criticism, said Alan Keenan, the International Crisis Group's senior analyst in Colombo.

Meanwhile, the countries with greatest leverage over Sri Lanka have remained relatively mute.

Japan, a major foreign donor, and China, which is financing a billion dollar port project, joined Russia and Vietnam in preventing the UN Security Council from discussing the war. The countries argue the conflict is an internal matter - akin to Tibet for China and Chechnya for Russia - and refuse to back sanctions or other tough action.

Neighbouring India, the regional powerhouse, has been ambivalent. While Tamils in southern India have agitated for action to protect the Tamils here, the government remains furious with the rebels for turning on Indian peacekeepers in the 1980s and for allegedly assassinating former Prime Minister Rajiv Gandhi in a 1991 suicide bombing.

The government's decision to bar journalists from the war zone has also made it largely invisible in the international media and ensured that no heart-wrenching television footage of civilian suffering could generate popular outrage for action around the world, Keenan said.

The international criticism has sparked a backlash among many Sri Lankans, who see it as the work of rebel sympathisers in foreign capitals.

Wanted posters have sprung up across Colombo accusing British Foreign Secretary David Miliband and US Secretary of State Hillary Clinton of “aiding and abetting terrorism.”

President Mahinda Rajapaksa brushed off the criticism.

“It is my duty to protect the people of this country. I don't need lectures from Western representatives,” he said.—AP