Syrian rebel fighters say they have captured a strategic northern military base used by the government to bomb opposition strongholds.Rebel fighters and militants from various Islamic groups, including the jihadist al-Nusra Front, took part in the offensive, an opposition spokesman said Friday.

They say they've seized control of buildings, ammunition and military equipment at the base in Idlib province, signaling a major blow to President Bashar al-Assad's forces.

The strategic base is used by government forces to send explosives to areas in the north, according to the opposition Syrian Observatory for Human Rights.

In addition to housing about government 400 soldiers, the group said, warplanes that attack the region take off from there.

"The Taftanaz air base has been completely liberated," said Hamza Abu Hussam, a spokesman for the Binnish Coordination Committee, a local opposition group.

"I went down to see with my own eyes and was able to get in."

In a video posted on YouTube, opposition forces from various groups cheered and chanted "God is great" after they took over the military airport.

CNN cannot independently verify the authenticity of the video.

 

War of words

The international push to end Syria's civil war is escalating, and so is the war of words between the government and the key player in the peace efforts.

Syria accused U.N. special envoy Lakhdar Brahimi of bias, hours before he is scheduled to meet top U.S. and Russian envoys Friday to discuss the conflict.

The accusation Thursday cast a shadow on efforts to end a war that, according to the United Nations, has killed more than 60,000 people in nearly two years.

Brahimi has "deviated from the essence of his mission and clearly unveiled his bias to circles known for conspiring against Syria and the interests of the Syrian people," Syrian state media reported.

The statement from Damascus was a response to Brahimi's BBC interview that effectively called on al-Assad to resign. He said the president had no place in the transition.

"I think what people are saying is, a family ruling for 40 years is a little bit too long," Brahimi said, according to the interview Thursday.

Al-Assad took over from his late father, who seized power in 1970 and ruled for three decades.

A pro-government newspaper also slammed Brahimi on Friday.

 

Securing chemical weapons

The escalating conflict and the president's efforts to retain his grip on power have sparked a push to ensure that chemical weapons are secure.

U.S. officials said they are working with nations in the Middle East to secure Syria's chemical and biological weapons sites.

"We're not talking about ground troops, but it depends on what ... happens in a transition," Defense Secretary Leon Panetta said Thursday.

Asked whether he had ruled out putting U.S. troops in Syria to secure such weapons, Panetta said: "You always have to keep the possibility that, if there is a peaceful transition and international organizations get involved, that they might ask for assistance in that situation. But in a hostile situation, we're not planning to ask for that."

The Syrian crisis started in March 2011, when peaceful protesters demanding democracy and reforms were met by a fierce government crackdown, which spiraled into an armed opposition movement and a civil war.

At least 41 people were killed Friday, the opposition Local Coordination Committees of Syria said.

 

CNN's Saad Abedine and Faith Karimi contributed to this report.