COLOMBO, Sri Lanka – The Tamil Tiger rebels admitted defeat in their 25-year-old war with the Sri Lankan government Sunday, offering to lay down their guns as government forces swept across their last strongholds in the northeast.

The government rejected the last-ditch call for a cease-fire, saying the thousands of civilians trapped in the war zone all have escaped to safety and there was no longer any reason to stop the battle. The military said the remaining guerrillas were still fighting.

With a war that has killed well over 70,000 people nearing its end, Sri Lankans poured into the streets in spontaneous celebration. President Mahinda Rajapaksa scheduled a nationally televised news conference for Tuesday morning at Parliament, where he was expected to tell the nation the war was over.

The fate of the Tamil Tigers' top commanders remained unclear, including the whereabouts of the reclusive rebel leader Velupillai Prabhakaran.

A senior military official said troops found the bodies of several rebel fighters who had committed suicide Sunday when troops surrounded them. The bodies were suspected of being Prabhakaran and his deputies, but the military was still trying to confirm their identities, the official said, speaking on condition of anonymity because he was not authorized to speak to the media.

The rebels, who once controlled a wide swath of the north, have been routed by government forces in recent months. On Sunday, Tamil Tiger suicide bombers targeted troops clearing out the last pockets of rebel resistance in the war zone and troops killed at least 70 rebels trying to flee by boat, the military said.

On Sunday afternoon, the tattered and nearly defeated rebel group offered to lay down its arms, saying it was acting to protect the wounded in the war zone.

"This battle has reached its bitter end," rebel official Selvarasa Pathmanathan said in a statement. "It is our people who are dying now from bombs, shells, illness and hunger. We cannot permit any more harm to befall them. We remain with one last choice — to remove the last weak excuse of the enemy for killing our people. We have decided to silence our guns."

Pathmanathan said the bodies of thousands of dead and wounded civilians lay on the battlefield.

Media Minister Anura Yapa dismissed the appeal, saying government forces had rescued all the civilians.

"We are looking after those people. We want to free this country from the terrorist LTTE," he said, referring to the group by its formal name, the Liberation Tigers of Tamil Eelam.

Military spokesman Brig. Udaya Nanayakkara said the rebels had not laid down their weapons. "Fighting is still going on in small pockets," he said.

With most journalists and aid workers barred from the war zone, it was not possible to verify the accounts of either side.

Troops on Sunday killed at least 70 rebels trying to escape the 0.4-square mile (one-square kilometer) patch of land that government troops have surrounded, the military said.

Thousands of Sri Lankans danced, set off celebratory fireworks and beat on drums in celebration Sunday after Rajapaksa made an initial declaration of victory.

"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 63,000 civilians fled the area over the past 72 hours, clearing the way for the government to finish off the rebels, Nanayakkara said Sunday.

"We're relieved to hear that all civilians have come out of the combat zone," U.N. spokesman Gordon Weiss said. More than 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.

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

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