TRIPOLI, April 1 (Xinhua) -- The Libyan government on Friday rejected the opposition's ceasefire proposal, saying it is "crazy" and lacks sincerity.

What the rebels offered was not peace, said Libyan government spokesman Mussa Ibrahim. "They are asking us to withdraw from our own cities ... If this is not crazy then I don't know what it is."

Meanwhile, the spokesman also accused the Western-led coalition forces of "crimes against humanity," saying allied warplanes had killed at least six civilians in a new attack.

"Some mad and criminal prime ministers and presidents of Europe are leading a crusade against an Arab Muslim nation," Ibrahim said.

Earlier on Friday, Mustafa Abdel Jalil, chairman of the opposition Interim Transitional National Council (ITNC), said they would agree to a ceasefire if (Muammar) Gaddafi withdrew his forces from all of Libya's cities and respected the rights of Libyans to choose sides.

Over the last two days, UN special envoy to Libya, Abdelilah Al-Khatib, has held talks in the embattled North African country with representatives of both the opposition and Gaddafi's government to seek a solution to the crisis.

Khatib again called the international community for the full implementation of UN Security Council resolutions 1970 and 1973.

Resolution 1970 imposed sanctions on Gaddafi and his inner circle and slapped an arms embargo against Libya. Resolution 1973 approved a "no-fly zone" over Libya to protect Libyan civilians.

The opposition's forces moved Friday to fortify Ajdabiya, a northeastern town between capital Tripoli and opposition's stronghold of Benghazi.

They have appealed to the international community for more weapons to fight the pro-Gaddafi forces.

"If the Gaddafi leadership keeps on its suppression of rebels, we are in the need for weapons ...to strike a military balance," Abdel Jalil told a press conference jointly held with UN special envoy Khatib.

Western-led forces bombarded "civilian and military locations" late on Friday in the towns of Khoms, about 100 km east of Tripoli, and Arrujban, about 190 km to the southwest, the Libyan state television said.

Many countries, such as Russia and China, have called for an immediate ceasefire and the start of peace talks in Libya, saying that diplomacy should be used instead of force to solve the crisis in the North African country.

Special Report: Foreign Military Intervention in Libya