Two aides to a Lebanese Druze minister were killed on Sunday when his convoy came under fire in an area of support for a rival Druze faction, in what the minister called an assassination attempt. 

Saleh al-Gharib, Lebanon's minister of state for refugee affairs, is close to pro-Syrian Druze leader Talal Arslan. 

The Mount Lebanon town near Aley where the incident took place is an area of support for Druze leader Walid Jumblatt, a fierce opponent of the Syrian government and rival to Arslan. His Popular Progressive Party (PSP) denied any involvement. 

Gharib said the incident had been "an armed ambush and a clear assassination attempt" in an interview with Lebanon's al-Jadeed TV. 

"There appears to be a decision to blow up the situation on the mountain," he said. 

The National News Agency reported that a PSP member was wounded in the incident.

Jumblatt, Lebanon's main Druze leader, and Arslan are historic rivals whose parties vied for posts in the national unity government formed earlier this year. 

The tensions on Sunday grew out of a plan by Foreign Minister Gebran Bassil, a Maronite Christian who is a political ally of Arslan, to visit the area, which led protesters to block roads. 

Bassil canceled the visit because of the protests, described as provocative by the PSP. 

Akram Chehayeb, a senior PSP official and minister of education, also urged calm, saying: "What happened is the result of poor judgment by some officials and is a recipe for strife on the Mountain." 

Prime Minister Saad al-Hariri, a Sunni Muslim, made contacts with the Druze parties, security chiefs, and Bassil "focused on the need to ease tension in Aley and to exert all efforts to calm the situation," his office said in a statement. 

Defence Minister Elias Bou Saab told the broadcaster LBC the army had deployed heavily in the area and called for calm. 

President Michel Aoun has called a meeting of Lebanese security chiefs on Monday, his office said. 

Arslan supporters blocked the main highway south with burning tires in protest over the incident, choking traffic for several hours.