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.
In an interview with Lebanon’s al-Jadeed TV, Gharib said the incident had been “an armed ambush and a clear assassination attempt”.
“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, described as provocative by the PSP, because of the protests.
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.”