Speaking at a news conference in the eastern city of Benghazi on Tuesday, Mustafa Abdel-Jalil, the head of the rebel Transitional National Council, gave forces loyal to Colonel Qaddafi until Saturday to negotiate a surrender. The offer related primarily to the coastal town of Surt, Colonel Qaddafi’s hometown and a focus of support for him, but also covered loyalist strongholds at Bani Walid and in the southern oasis town of Sabha.

“By Saturday, if there are no peaceful indications for implementing this, we will decide this matter militarily. We do not wish to do so but we cannot wait longer,” Mr. Abdel-Jalil said.

NATO, which has been conducting an air campaign under a United Nations mandate since March, said it was aware of reports “from a few hours ago” that there had been discussions between loyalist and rebel supporters in Surt.