BEIRUT: A video posted on the Internet shows Sunni Muslim rebels burning a Shiite mosque in north Syria - a sign that the country's civil war is spiralling into a sectarian conflict.

Dozens of fighters dressed in camouflage gear with Sunni-style beards are shown in the footage congratulating and kissing each other outside the burning Shiite 'Husseiniya' mosque. They also burned flags they said were Shiite.

A fighter holding a rifle says the rebel group is destroying the "dens of the Shiites and Rafida," a derogatory term meaning "deserters," which is used against Shiites.

Reuters could not independently verify the video, which was posted on YouTube on Wednesday and purports to be filmed in the northern town of Jisr al-Shughur.

Syria's revolt, like its population, is majority Sunni. President Bashar al-Assad and his late father President Hafez al-Assad are from the minority Alawite sect, an offshoot of Shiite Islam, that has dominated power since the 1960s.

Minority groups fear an Islamist takeover and many Christians, Shiites and Kurds are reluctant to support an armed revolt that included several Sunni extremist rebel units.

Syrians took up arms against authorities after attacks by Assad's security forces on protests that called for a democratic Syria. Since March 2011, 40,000 people have been killed.