(CNN) -- Sri Lanka's quarter-century-long civil war is in its final phase, the government suggested Friday, as its troops pounded Tamil Tiger rebels in the country's north.
This picture, released by the Sri Lankan defense ministry, is said to be of a dead Tamil Tiger body captured after fighting on May 14, 2009.
The rebels -- formally known as the Liberation Tigers of Tamil Eelam (LTTE) -- have fought for an independent state in Sri Lanka since 1983.
As many as 70,000 people have been killed since the civil war began.
President Mahinda Rajapaksa said the end of the current military push, which is often referred to as a civilian rescue mission, is less than 48 hours away. He spoke from Jordan on Friday, where he's attending an economic summit.
"The Tamil civilians held hostage by the LTTE in small area of land in the north would be rescued, and the Tamils would be saved from the threat of LTTE terrorism," Rajapaksa said.
In a rapid military push, Sri Lankan forces have squeezed Tamil Tiger fighters into approximately 1.5 square miles (four square kilometers) of coastal land. The United Nations estimates that more than 50,000 civilians are trapped there. CNN's Paula Newton reports on the plight of trapped civilians »
The chunk of land, known as the no-fire zone or civilian safety area, was under siege by government forces Friday, according to Tamilnet.com, a rebel Web site.
"The entire safety zone area is in smoke ... as shelling by the Sri Lanka army was destroying all the structures within a narrow strip of coastal land, which is densely populated with tens of thousands of people," Tamilnet said.
Humanitarian aid groups have reported mass civilian casualties in the fighting.
"The government is moving forward in extremely difficult circumstances. After all, the ... Tamil Tigers are seeded amidst the middle of all these civilians. It's very difficult to weed out and identify who is a fighter and who is not," said Gordon Weiss, a U.N. spokesman.
"It makes it very very dangerous for civilians, and it explains the very large toll on civilian life that we've seen at this point."
Weiss called the fighting a "bloodbath" at the beginning of the week.
The situation had worsened by Friday, the International Committee of the Red Cross said. It suspended evacuation and medical rescue operations in the no-fire zone. Aid agencies had been stuck offshore, unable to deliver badly needed relief supplies and evacuate civilians.
"Our staff are witnessing an unimaginable humanitarian catastrophe," said Pierre Krahenbuhl, the Red Cross' director of operations. "No humanitarian organization can help them in the current circumstances. People are left to their own devices."
The U.N. Security Council and U.S. President Barack Obama on Wednesday called for both sides to protect civilians and allow humanitarian aid into the conflict zone. Watch frustration build at the United Nations »
In a statement at the White House, Obama urged Sri Lankan government troops to halt the "indiscriminate" shelling of civilians trapped with the remnants of the country's Tamil Tigers. He also prodded the rebels to stop using civilians as human shields.
Security Council members issued a statement demanding "that all parties respect their obligations under international humanitarian law."
A Red Cross worker was killed Wednesday during shelling in the conflict zone in Sri Lanka -- the third aid worker killed in six weeks -- the Red Cross said.