By Nadim Ladki, Beirut – Lebanon’s army deployed more soldiers in Beirut on Monday after the killing of a demonstrator raised fears anti-government protests could turn into sectarian violence. Arab League Secretary-General Amr Moussa warned the crisis could worsen and indicated he had discussed ideas for a solution with Lebanese officials during a 24-hour visit to Beirut.

Security sources said the military increased its forces in Sunni districts that Shi’a protesters drive through to get to central Beirut where the Hezbollah-led opposition is holding a sit-in to try to topple the Western-backed government.These districts saw clashes between residents and protesters on Sunday – from stone-throwing to fights with knives.

In the most serious incident, gunmen fired assault rifles at a group of protesters in a Sunni neighbourhood, a stronghold for the anti-Syrian majority coalition, killing one man.The body of Ahmed Mahmoud was brought to the protest site, where thousands of anti-government demonstrators read Qur’anic verses over a coffin wrapped in a Lebanese flag.

The opposition plans a mass funeral on Tuesday and said the death would not halt its drive to unseat the government.

"Siniora out, we want a free government," the crowd chanted during a night rally at the tent camp, referring to the Western-backed Sunni prime minister, Fouad Siniora.

A few thousand soldiers and police were deployed around Beirut on the fourth day of the protests. Troops sat atop armoured vehicles at road junctions.

Many politicians and observers have said the crisis could spill over into sectarian strife in a country that has gone through two civil wars in the last 50 years.

Lebanon’s most senior Shi’a cleric Grand Ayatollah Mohammad Hussein Fadlallah called for unity.

"One of the most dangerous things is the devilish state of sectarian instigation by some political symbols … which is making the political dispute open to sectarian sensitivities," Fadlallah said on Monday.

The leader of the anti-Syrian majority coalition, Sunni Saad al-Hariri also urged calm and asked his supporters to ignore what he called provocations.