Now that the uprising in Syria has turned into a heavily armed conflict, many in the region are worried that the violence will spread beyond its territory.
Syria borders Iraq, Turkey, Jordan and Israel, as well as Lebanon, where clashes erupted last Friday in the northern coastal city of Tripoli.
Sunni Muslims in one Tripoli neighborhood began protesting against Syrian President Bashar Assad. They put up a huge banner on the side of a mosque that had a picture of Assad, wearing a military uniform, with a big red X across his face.
Syrian troops have fired rockets and mortars at neighborhoods in the city of Homs that have most fiercely resisted the government throughout the uprising.
Mainstream journalists are barred from entering Homs, so a team of activists decided to record the offensive themselves. The activists positioned their cameras atop buildings in the city. Each morning the view is blue sky, a minaret, a sea of rooftops. Then come the booms.
From inside the Syrian city of Homs, where activists say several hundred people have been killed by government forces in the past week and troops are preparing for what could be a "ground offensive" in coming days, residents say the "situation could not be more dire," NPR's Kelly McEvers reports.