Syrian activists say cease-fire is collapsing (CBS News) DEMASCUS, Syria - The first members of an U.N. observer team arrived in Syria late Sunday, charged with overseeing a ceasefire that seems to be collapsing. CBS News correspondent Elizabeth Palmer reports that government forces, once again, shelled the city of Homs. Just a day after a United Nations Security Council vote, the first six of an eventual 30 unarmed military observers arrived in Damascus tonight. "We believe the mere presence of blue helmets on the ground in one or two locations which have seen conflict and tension will reduce tensions," said Ahmed Fawzi, a spokesman for Peace Plan Envoy Kofi Annan. That tension has escalated into an all-out offensive in the city of Homs. Anti-government activists say their video shows the cease fire there has broken down completely. Advance team of U.N. observers arrives in Syria McCain: U.S. must lead in Syria Syrian protesters hit the streets after cease-fire Raja al Nasser, an opposition activist in Damascus, says it is crucial that this violence stop and the U.N. observers get to work immediately to reinforce the cease fire. "It is the very last chance for us to reach a political solution," Nasser says. But on "Face the Nation" this morning, Senator John McCain said the US - and other countries - should actually arm anti-government fighters. So we need to get a sanctuary for the Free Syrian Army. We need to get them supplies. We need to get them weapons," McCain said. It's a controversial idea and one opposition activists inside Syria don't like. They believe it would ignite a civil war. The only way to defeat Bashar al-Assad's government, they say, is at the negotiating table, backed by strong international consensus.