At least 23 people have been killed in Israeli air strikes on two houses in central Lebanon where displaced families were reportedly living, the Lebanese health ministry says.

Israeli officials are insisting on maintaining a capacity to strike Lebanon at any moment as part of conditions to secure a ceasefire with Iran-backed Hezbollah, France's foreign minister said on Wednesday.

The conflict between Israel and Hezbollah has deepened in recent days despite diplomatic efforts to move toward a temporary truce.