Sri Lanka's army said the "final push" is under way to capture the remaining sliver of beach held by Tamil Tiger rebels. The government and military predict all of the remaining trapped civilians in rebel territory will be freed by Sunday.
Two Army divisions are closing in on the Tamil Tiger rebels from both the north and the south on a narrow stretch of coastline.
Military officials told VOA News the Liberation Tigers of Tamil Eelam, who once controlled a significant portion of the north and east of the island, now hold a mere three square kilometers.
A top defense spokesman, Lakshman Hulugalle, said soldiers are unsure how many armed rebels they are still confronting, after days of intense fighting, because the Tamil Tigers are trying to blend in with civilians.
"They're among civilians so they can fight as civilians. So it's very difficult to say how many numbers are fighting," he said.
The military has accused the rebels of holding the Tamil civilians as human shields.
Thousands may have died in the past week due to shelling both sides blame on the other.
State television is showing scenes of fires sweeping across the tropical beach and airing interviews of those who escaped saying they were shot at by the rebels.
Some of the civilians are fleeing by floating on tire tubes and rafts across a lagoon.
Lakshman Hulugalle, who heads the military's national security media center, told VOA the rebels can not be finished off until soldiers are assured the civilians are safe.
"Almost 6,000 people have come into the government controlled area. Hopefully, next 24 hour or 48 hours, the balance of people will come into our area," he said.
The United Nations secretary-general has dispatched his top aide to return to Sri Lanka to try to safeguard the tens of thousands of civilians who may still be trapped in the combat zone.
The Red Cross, unable any longer to bring in food or evacuate the wounded and sick, said its workers are witnessing "an unimaginable humanitarian catastrophe."