Israeli ground forces have "started to operate" around a northern Gaza town, expanding an anti-Hamas offensive that will apparently see residents kept out indefinitely.

Several large airstrikes hit Beirut's southern suburbs early Thursday morning, including one on a site adjacent to Lebanon's only international airport.

Israel is expected to begin implementing “4-hour pauses" in areas of northern Gaza each day, beginning Thursday, the White House said.

Israel's military has warned that Hamas militants from Gaza are still fighting inside Israel after they infiltrated southern communities and left a reported 300 people dead. Prime Minister Benjamin Netanyahu has told Israelis they are going into a "long and difficult war".