BEIRUT, LEBANON - Supporters of Lebanon's U.S.-backed government and opponents battled with rockets and machine guns in the mountains overlooking Beirut on Sunday as clashes shifted to outside the capital.

Beirut was quiet a day after Hezbollah gunmen left the streets, heeding an army call for the Shiite fighters to clear out. The city had been the focus of four days of Sunni-Shiite clashes that culminated with Hezbollah seizing large swaths of Muslim West Beirut, demonstrating its military might in a showdown with the government.

So far, 38 people have been killed in clashes that began Wednesday, the worst sectarian violence since Lebanon's 1975-1990 civil war.

The violence grew out of a long-simmering power struggle between the Hezbollah-led opposition and the U.S.-backed government. The opposition quit the Cabinet 17 months ago, demanding a veto over all government decisions. The deadlock has kept parliament from electing a new president since November.

Hezbollah's demonstration of its power over the past week was a blow to Washington. The U.S. has long considered Hezbollah a terrorist group and condemned its ties to Syria and Iran. The Bush administration has been a strong supporter of Prime Minister Fuad Saniora's government and its army for the past three years.

The conflict also has increased concerns in the Middle East and the West over Iran's growing influence and its intentions in the region.

The worst violence over the weekend was outside of Beirut. On Sunday, heavy fighting broke out in the central mountain town of Aytat and the sounds of heavy machine gunfire and explosions from the clashes rolled across Beirut, 9 miles away.

As the fighting raged in the mountain region, black smoke could be seen billowing from Druse villages.

Pro-government supporters of Druse leader Walid Jumblatt and Shiite gunmen exchanged rockets and machine gunfire.

The clashes came a day after Hezbollah accused Jumblatt's followers of killing two of their supporters and kidnapping a third.

The Aley region is predominantly Druse and Maronite Christians. However, two villages in the area are dominated by Shiites, many of them Hezbollah supporters.

Jumblatt called on his top Druse opponent to mediate a cease-fire and hand over the mountain region to Lebanese troops.

Shortly afterward, Talal Erslan, the leading Druse leader in the opposition, called at a news conference for all opposition groups to cease fire immediately in the mountains. He urged Jumblatt's supporters to hand over their weapons and offices to the army.

Jumblatt, speaking to private LBC television, implicitly called on his militiamen to give up their positions to the army.