Fighters for the new Libyan authorities say they are squeezing Gaddafi loyalists into smaller and smaller areas of the former leader's home town of Sirte.
But the BBC reports that despite a heavy bombardment, they have not yet been able to capture a key target, a sprawling convention centre where fierce fighting is continuing.
The National Transitional Council (NTC) chairman Mustafa Abdel Jalil said there is a very vicious battle in Sirte.
"Today our fighters are dealing with the snipers that are taking positions and hiding in the city of Sirte" he said.
Civilians continue to leave Sirte on foot and by car.
They were stopped and searched by NTC forces at checkpoints.
The NTC gave civilians the opportunity to leave before the assault began.
However, thousands remained in the city, unable to get out, fearful after warnings from pro-Gaddafi fighters that they would be attacked by interim forces if they surrendered.