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.

The Israeli military pounded Beirut's southern suburbs with airstrikes on Tuesday, mounting one of its heaviest daytime attacks yet on the Hezbollah-controlled area, and struck the middle of the country where more than 20 people were killed.

Israeli airstrikes killed at least 46 people in the Gaza Strip in the past day, including 11 at a makeshift cafeteria in an Israeli-declared humanitarian zone, medics said. In Lebanon, warplanes struck Beirut's southern suburbs and killed 33 people elsewhere in the country on Tuesday.