BEIRUT, Lebanon — Prime Minister Saniora of Lebanon won a new term yesterday with the backing of a pro-American coalition, angering the Hezbollah-led opposition that had pressed for a change in leadership.

The decision came amid a two-day outbreak of low-level violence between supporters of the country’s two main political camps.

Mr. Saniora was named anew to the government’s most powerful executive position just three days after a former army of chief of staff, Michel Suleiman, was elected president and assigned to name a government following an agreement meant to end a 19-month political crisis.

“Our national unity and coexistence are what we hold most precious and are the secret to the survival of this country,” Mr. Saniora said in a televised address. “I address myself to my brothers in the nation from all sides and backgrounds with an open mind.”

Mr. Saniora’s victory appeared to catch the opposition off guard. Syrian- and Iranian-backed factions and most analysts said they believed the majority pro-American coalition known as the March 14 movement would nominate parliamentary majority leader Saad Hariri, the leader of the country’s Sunni Arab community.