France said on Friday it had summoned the Israeli ambassador after UN peacekeepers in Lebanon said Israeli fire on their headquarters wounded two staff.

UN peacekeepers said Israeli fire on their headquarters in south Lebanon on Thursday injured two Blue Helmets, sparking condemnation from European members of the mission. No French soldiers were hurt in Thursday's incident, France said.

"These attacks constitute serious violations of international law and must cease immediately," the French foreign ministry said in a statement, adding that it condemned "deliberate Israeli fire" against the UN Interim Force in Lebanon (UNIFIL).

"The Israeli authorities must explain themselves. France is therefore summoning today the Israeli ambassador to France."

France, which has had a military presence in Lebanon since 1978, contributes about 700 troops to the UN Interim Force in Lebanon, according to the French defence ministry.

"We pay tribute to all UNIFIL personnel, to our French contingent and to all contingents, for their ongoing commitment and professionalism under these difficult conditions," the French foreign ministry said.

Paris reiterated "the urgent need for a cessation of hostilities and a diplomatic settlement."

Israel acknowledged its forces had opened fire in the area, saying the Hezbollah fighters on whom it is waging an escalating war operate near UN posts.

Italy, a major contributor of troops to the force, said the acts "could constitute war crimes" while Washington said it was "deeply concerned."

UNIFIL, which has about 10,000 peacekeepers stationed in south Lebanon, has called for a ceasefire since an escalation between Israel and Lebanese group Hezbollah on September 23, after a year of cross-border fire. (AFP)