The U.N. Interim Force in Lebanon criticized Israel on Wednesday for dropping four grenades from a drone near peacekeepers in what it called one of the most serious attacks on its personnel since the November cease-fire.

The truce ended more than a year of hostilities and two months of open war between Israel and the Lebanese armed group Hezbollah, but the United Nations has reported several attacks on its positions in south Lebanon since.

"Yesterday morning, Israel Defense Forces drones dropped four grenades close to UNIFIL peacekeepers working to clear roadblocks hindering access to a U.N. position," the force said, referring to the Israeli military.

"One grenade impacted within 20 meters and three within approximately 100 meters of U.N. personnel and vehicles," it added.

The Israeli army did not immediately respond to an AFP request for comment.