BEIRUT, Lebanon - Shiite Muslims began burying their dead on Monday, a day after seven protesters died in rioting and clashes in Beirut's southern suburbs that were reminiscent of Lebanon's 15-year civil war.

The government declared a day of mourning, and calm returned to the capital city's Shiite neighborhoods. Prime Minister Fuad Saniora ordered schools and universities closed for a day in an attempt to prevent more friction between political groups.

Sunday's death toll was the highest for a street disturbance since the country plunged into a crisis three years ago with the assassination of former Prime Minister Rafik Hariri, a turning point in Lebanese politics that sparked local and international outrage and forced the Syrian army to withdraw after 30 years of control.

What started as an angry protest by government opponents against electricity rationing quickly degenerated into street violence and clashes with troops. The violence was confined to mainly Shiite areas, and the army deployed in what appeared to be an attempt to prevent the unrest from spreading to nearby Sunni Muslim and Christian areas.

The fighting ignited memories of the 1975-90 civil war and came as Lebanon is in the middle of a political fight over who will become its next president. The clashes erupted along the war's former demarcation line between Christian and Muslim areas and near a district where the bloody conflict, which killed 150,000, began. A hand grenade tossed by rioters into that district, Ein el-Rummaneh, injured four people.

"Our nation is going through its most difficult and dangerous times and circumstances, threatening the collapse in our hands of what we have built in the past years," Saniora said in a statement late Sunday.

He urged people to wait for an investigation into how the shootings occurred and to rally behind the army, declaring the victims as "martyrs of all the nation."

The protests began Sunday with hundreds of Shiites burning tires and blocking some major roads in the capital's southern suburbs. Lebanese soldiers then fired into the air to disperse the crowd. It was unclear how the deaths occurred, whether the soldiers also intentionally fired on civilians or if another party opened fire.

The rioting spread with news of the first death and protesters burned tires and briefly blocked the highway to Beirut's international airport.

Troops in armored carriers and others on foot intervened as opposition officials urged their supporters to clear the streets, saying they were not involved in the rioting.

The mood was somber but peaceful as Shiites began burying their dead Monday, as hundreds of people took part in three funerals. Women threw rice, and Koranic verses blared from loudspeakers as three separate processions got under way.

Traffic was thinner than usual throughout the city. In the troubled neighborhoods, troops were on the streets, shops were closed and some residents were clearing broken glass and inspecting their property.

"Why did I have to bear the brunt of their anger?" Samir Adada said Monday as he stood next to his gutted Jeep Cherokee that was damaged in the riots.

Lebanon is embroiled in its worst political crisis since the civil war. Former President Emile Lahoud left office on Nov. 23 without a successor, and parliament has so far failed to elect the army chief to replace him amid bickering between the parliament majority and the opposition.

The pro-government coalition, which is backed by the United States and pro-American Arab states, blamed the violence on Syria and Iran, who back the opposition led mainly by the Shiite militant Hezbollah and Amal. But Hezbollah blamed the governmen. -AP