AFP - The United Nations evacuated hundreds of severely wounded civilians from behind rebel lines in Sri Lanka on Thursday as government troops fought to secure final victory over Tamil separatists.
Human rights bodies have called for immediate steps by both the Colombo government and the Liberation Tigers of Tamil Eelam (LTTE) to save up to 250,000 civilians trapped in the combat zone in the north of the island.
Troops are pushing deep into the jungles of Mullaittivu district in what the defence ministry has described as the final phase of operations against the Tigers, who have fought for more than 30 years for a separate Tamil homeland.
"About 350 critically wounded civilians, including 50 children, crossed the front lines," UN spokesman Gordon Weiss said, adding that the evacuations were the result of lengthy negotiations with the rebels.
A convoy of ambulances had been trapped for days behind Tiger front lines in Mullaittivu district, with the rebels refusing permission for it to leave.
The New York-based Human Rights Watch said fighting between Sri Lankan troops and the LTTE had left an estimated 250,000 non-combatants stranded, urging both sides to do everything possible to spare innocent lives.
"The situation for hundreds of thousands of vulnerable civilians trapped in the Wanni war zone is becoming increasingly dangerous," said Brad Adams, Asia director at Human Rights Watch.
"Both the government and the LTTE need to take urgent action to prevent large-scale civilian deaths."
Amnesty International added its voice to that of the International Committee of the Red Cross and foreign governments in expressing fears of an unfolding humanitarian crisis in the north of the South Asian island nation.
"People displaced by the conflict are experiencing acute shortages of humanitarian aid, especially food, shelter and medical care," said Yolanda Foster, Amnesty's Sri Lanka specialist.
"There has been no food convoy in the area since 16 January."
Foster said the priority was to provide medical attention for the wounded, saying: "Preventing civilians from accessing medical care constitutes a war crime."
After a series of battlefield victories, Sri Lankan forces were fighting their way towards the remaining jungle pockets still held by the Tigers.
The guerrillas had positioned their long-range artillery guns in an area declared a "safe zone" for civilians and were firing at the military from there, the defence ministry said.
The Tigers wanted to create a "last-minute civilian tragedy" because the army was about to defeat them, it said.
More than 250 civilians have been killed and over 1,000 injured since the beginning of January, said T. Varatharajah, regional director of health services in Mullaittivu.
"There are dozens of unclaimed bodies lying in the hospital mortuaries because no relatives are coming forward to claim them," Varatharajah told AFP by telephone.
The pro-rebel Tamilnet.com website has said the toll is far higher.
Sri Lanka has dismissed charges of widespread civilian deaths, with military spokesman Brigadier Udaya Nanayakkara branding such claims part of a "cheap propaganda exercise" by the Tigers.
However, Indian Foreign Minister Pranab Mukherjee, on a hastily-arranged visit to Sri Lanka, said instant measures needed to be taken to protect civilians.
The territory controlled by the Tigers has been shrinking since mid-2007, and the guerrillas lost their last urban centre when the military seized the town of Mullaittivu on Sunday.
Government forces are also battling to capture 30 kilometres (18 miles) of coast north of the bombed-out town.
Seizing the coastline would leave the remaining LTTE forces -- and possibly Tamil Tiger leader Velupillai Prabhakaran -- encircled by troops.