U.N.: Heavy fighting in Syria outside Homs United Nations observers in Syria reported Monday that rebels and government were engaged in heavy fighting on the approaches to the city of Homs. DAMASCUS, Syria, June 11 (UPI) -- United Nations observers in Syria reported Monday that rebels and government were engaged in heavy fighting on the approaches to the city of Homs. It was not clear if a major government offensive against Homs was under way, though shelling and gunfire resonated through the area, the U.N. Supervision Mission in Syria said in a written statement. "Observers reported heavy fighting in Rastan and Talbiseh, north of the city, with artillery and mortar shelling, as well as firing from helicopters, machine guns and smaller arms," the statement said, "In Talbiseh, U.N. observers reported that the Free Syrian Army captured Syrian Army soldiers. The impact from heavy artillery shelling and machine gun firing was heard and seen over the neighborhood of Khaldiyeh in the city center. Casualty reports were sketchy and unconfirmed. A large number of civilians were believed trapped in the combat zone. The United Nations said it was attempting to negotiate an arrangement that would allow the evacuation of civilians. Meanwhile, the new leader of the opposition Syrian National Council called on government officials to defect. Speaking in Istanbul, Turkey, Abdulbaset Sieda said the group was not seeking "a foreign war or intervention. Sieda also called on officials in Syria, Russia and China "to think carefully about the situation now because the whole stability of the region -- if not the whole stability of the world -- is at stake here." "We would like to call upon them to support the Syrian people," he said. British Foreign Secretary William Hague said Western airstrikes in Syria remained a possibility.