Beirut: Lebanon slipped deeper into turmoil yesterday as troops shot dead a Sunni cleric and his companion when their convoy failed to stop at a checkpoint in northern Lebanon.

Shaikh Ahmad Abdul Wahid, a Sunni cleric, and his companion Khalid Miraib, both members of the Lebanon-based March 14 political alliance against Syrian President Bashar Al Assad, were shot in their car.

Parliamentarians representing the area asserted they were "murders" and called for the fall of the Lebanese government.

Prime Minister Najeeb Mikati has appealed for calm in the wake of the cleric's death, even as the army said it "deplored ... the regrettable incident that took place near a checkpoint" and that it had opened an investigation.

However, Mikati's words did little to soothe the seething anger as residents set fire to tyres and blocked several roads over what they viewed as the Lebanese army's tacit support for the Syrian regime.

Lebanese opposition chief Sa'ad Hariri urged the "residents of Akkar to remain calm and not to fall into the trap of igniting sectarian tension".

Frustration with the Lebanese government was not restricted to Sunni citizens. Many others felt the ban on travel to Lebanon, issued by Qatar, Bahrain and the UAE on Saturday, was a clear message to Mikati to "reconsider his blatantly pro-Syrian position", given how important Gulf tourism is for the Lebanese economy.

Meanwhile, the situation across the border was even more disturbing with reports of at least 21 people being killed in violence across Syria yesterday.

Those killed yesterday included three children in a village in central Hama province, the Syrian Observatory for Human Rights said.