COLOMBO: The last remaining civilians trapped by fighting in northern Sri Lanka poured across the front lines Sunday as Tamil Tiger suicide bombers targeted troops in the final battles of the quarter-century civil war, the military said.

Troops on Sunday killed at least 70 rebels trying to escape the 0.4-square mile (1-square kilometer) patch of land that government troops have surrounded, the military said. However, the Tamil Tigers' top commanders remained at large. The military said the rebel leadership was likely still in the conflict zone and was planning a mass suicide.

Thousands of Sri Lankans poured into the streets Sunday morning, dancing and setting off celebratory fireworks, after President Mahinda Rajapaksa declared victory in the country's quarter-century civil war with the separatist rebels.

"We are celebrating a victory against terrorism," said Sujeewa Anthonis, a 32-year-old street hawker.

As the fighting raged on in recent days, concerns mounted for the fate of the tens of thousands of civilians trapped in the war zone amid heavy shelling and intense fighting.

But all 50,000 civilians fled the area over the past 72 hours, clearing the way for the government to finish off the rebels, military spokesman Brig. Udaya Nanayakkara said Sunday. With journalists and aid workers barred from the war zone, it was not possible to verify the assertion.

"We're relieved to hear that all civilians have come out of the combat zone," U.N. spokesman Gordon Weiss said. A total of nearly 250,000 civilians have fled the fighting in recent months.

Rights groups have accused the rebels of holding the civilians as human shields, which the rebels have denied.

The U.N. says 7,000 civilians were killed and 16,700 wounded from Jan. 20 through May 7. Health officials say more than 1,000 have been killed since then in heavy shelling that rights groups and foreign governments have blamed on Sri Lankan forces. The government denied shelling the area.

The war zone was wracked by chaos Sunday, as troops sought to mop up the final pockets of resistance, Nanayakkara said. At least one suicide bomber attacked troops in the morning, the latest in a wave of rebel attacks on the advancing forces in recent days, he said. He declined to say what damage the attack caused.

The pro-rebel Web site TamilNet, citing a doctor in the area, said the bodies of hundreds of wounded and dead people lay strewn across the battlefront.

Early Sunday, insurgents tried to escape in six boats across a lagoon. But army troops thwarted the rebel attempt, killing a large number of rebels, said Nanayakkara.

So far, 70 bodies of rebel fighters have been recovered, he said.

Government forces have been hunting for reclusive rebel leader Velupillai Prabhakaran and his top deputies for months, but it was unclear if they remained in rebel territory or had already fled overseas. The defense ministry issued a statement Saturday saying that he and his deputies were likely still in the war zone and planning a mass suicide.

Rajapaksa raced home from a visit to Jordan after declaring victory in the war.

"I will be going back to a country that has been totally freed from the barbaric acts of the LTTE," he said in Jordan on Saturday, referring to the rebels by their formal name, the Liberation Tigers of Tamil Eelam.

Upon his arrival early Sunday, ministers and well-wishers cheered as he descended from his plane and Buddhist, Catholic, Hindu and Muslim clerics blessed him.

Many of those celebrating said the war had badly damaged the country for three decades.

"This victory will ensure a better future for the coming generations," said Prasanna Jayawardena, 38, who was lighting firecrackers in the streets of Colombo.

The rebels, who once controlled a de facto state across much of the north, have been fighting since 1983 for a separate state for minority Tamils after decades of marginalization by the Sinhalese majority. Responsible for hundreds of suicide attacks — including the 1991 assassination of former Indian Prime Minister Rajiv Gandhi — the Tamil Tigers have been branded terrorists by the U.S., E.U. and India and shunned internationally.

The rebels also controlled a conventional army, with artillery units, a significant navy and even a tiny air force.

After repeated stalemates on the battlefield, the military broke through the rebel lines last year and forced the insurgents into a broad retreat, capturing their administrative capital at Kilinochchi in January and vowing to retake control over the rest of the country.

A triumph on the battlefield appeared inevitable after government forces captured the last bit of coastline under rebel control Saturday, surrounding the remaining insurgents.

The rebels have insisted that if defeated in conventional battle, they will return to their guerrilla roots.