Israel expanded its bombardment in Lebanon, hitting Beirut's southern suburbs with airstrikes and striking a Palestinian refugee camp in northern Lebanon.

An Israeli strike on a mosque in the Gaza Strip early Sunday killed at least 19 people, Palestinian officials said, as Israel intensified its bombardment of northern Gaza and southern Beirut in a widening war with Iran-allied militant groups across the region.

Israeli airstrikes are continuing across Lebanon and in the capital. A U.S. official told ABC News on Sunday that small-scale cross-border Israeli ground operations may have already begun, as a prelude to a wider offensive into southern Lebanon in pursuit of Hezbollah targets.

An Israeli airstrike hit a mosque in central Gaza and Palestinian officials said at least 19 people were killed early Sunday. Israeli planes also lit up the skyline across the southern suburbs of Beirut,

Israel shifted some of its focus from Hamas to Hezbollah, which holds much of the power in parts of southern Lebanon and some other areas of the country.

Israel continued its intense airstrike campaign across Lebanon, which included several strikes in Beirut's southern suburbs and one in the center of the city.

Israeli attacks continued on Saturday as rumours circulated over the fate of killed Hezbollah leader Hassan Nasrallah’s successor, Hashem Safieddine