The US State Department released satellite imagery of tens of thousands of Sri Lankan civilians squeezed into the last small strip of land controlled by Tamil Tiger rebels.
The State Department said a recent image of the conflict zone released yesterday shows about 25,000 tents packed into a coastal strip about 21 sq kilometers large.
Based on the number of tents, they estimated about 125,000 people were in the conflict zone before about 60,000 civilians escaped during the last two days.
Human rights groups say the Liberation Tigers of Tamil Eelam are holding many people in the enclave against their will and using them as human shields. Those groups also have accused the government of indiscriminate shelling in the region. Both sides deny the allegations.
Thousands of civilians also fled packed in small boats and were picked up by navy patrols and transported to camps where Tamils who have escaped the war are being held. More than 2,000 people in about 100 boats were picked up Monday.
The United Nations and others have called for a negotiated truce to allow civilians to leave the rebel-held coastal strip.
The Sri Lankan government has refused to heed international pleas to halt the fighting, saying it is on the verge of crushing the separatists and putting an end to the 25-year-old war.