Driving through Syria's unofficial civil war (CBS News) DAMASCUS - The fierce battle in the city of Homs is on the southern edge of a whole area of central Syria - where the army and the armed opposition have been fighting from positions that are sometimes just hundreds of yards apart. A police barrier marks the start of the war zone, just north of Homs - fighting has closed Syria's main highway but the United Nations monitoring mission is allowed through, and CBS News went in with them. Driving down the highway, there is mile after mile of devastation on either side. Dug in all along the way are Syrian tanks and artillery - some still doing the shelling which has battered parts of Homs and other cities, others wrecked and burned in attacks by the rebel forces. Every few hundred yards along the road there are Syrian military installations, but as soon as CBS News stopped with the U.N. staff, Free Syrian Army members - the rebels - came out to talk to us. Video: Syrian city of Homs turned into war zone New tactics, fresh violence stoke fear in Syria Annan "gravely concerned" amid Syria escalation They appeared from an abandoned building - anxious to talk to the U.N. monitors. Most civilians have now fled from the towns along the highway. But less than a mile further up the road, a woman appears outside her ruined home and waves to the convoy, keen for someone to hear her story. "Look what's happening to us," she says. Are we not people? She says a missile from a Syrian army helicopter destroyed the row in shops she's standing in front of. A young opposition fighter agrees, and a helicopter suddenly appears overhead. The U.N. has confirmed that Syrian forces attacked the opposition from the air in recent days, so the U.N. convoy decides it's time for us to go. We pass through Syrian army checkpoints. We'd like to hear their story, too, but they won't talk to journalists. They are dug in, with their heavy armor, in force. But it is not enough force to keep a rebel flag from hanging from an overpass just up the road. While Syrians and international diplomats are reluctant to call this a civil war - that is what it looks like in central and northern areas of the country.