Australia has warned its citizens not to travel to Israel and urged Australians there to leave the country while commercial flights remained available, citing the conflict between Israel and the Lebanon-based militant group Hezbollah.

"The Australian government has serious concerns the security situation in Israel and the Occupied Palestinian Territories could deteriorate rapidly," Foreign Minister Penny Wong said in a post on X late Monday.

There continues to be a high threat of military and terrorist attacks against Israel and Israeli interests across the region, the Australian government's travel advisory said.

Some airlines have reduced and suspended flights to Israel after the escalation in conflict caused airspace closures, the advisory said.

Israel on Monday expanded its targets in its war with Hezbollah, killing at least 21 people in an airstrike in north Lebanon, health officials said, while millions of Israelis took shelter from projectiles fired back across the border.

Four Israeli soldiers were killed on Sunday in central Israel after a Hezbollah drone strike.