A hoped-for cease-fire in Syria between troops loyal to Syrian President Bashar Al-Assad and rebel groups broke down within hours. International mediator Lakhdar Brahimi had tried to broker a deal for a four-day truce over the Muslim holiday of Id al-Adha, which began Friday. For the first few hours it seemed that the truce might take hold, but by the end of the day activists said 151 people had been killed in bombings and shootings. On Saturday, a Syrian warplane flattened a three-story building in a Damascus suburb, killing at least eight men. Syrian army troops and rebels also fought a fierce battle for the main road linking Aleppo, Syria’s largest city, with Damascus, the capital. A British-based Syrian human rights group says at least 30,000 people have been killed in 19 months of fighting, many of them civilians.