An Israeli strike on a school sheltering displaced people in Gaza killed at least 27 people on Thursday, with the toll likely to rise, Palestinian medical officials said.

Israel has continued to strike at what it says are militant targets across the Palestinian enclave even as attention has shifted to its war against Hezbollah in Lebanon and rising tensions with Iran. It launched a large-scale air and ground operation against Hamas in northern Gaza earlier this week.

An Israeli strike hit a road linking Syria and Lebanon Thursday as Israel tries to cut off supply routes of Hezbollah, a war monitor said.

Israel has increased it strikes on Syria since it upped its air raids on what it says are targets of Hezbollah in Lebanon more than two weeks ago, notably killing the leader of the Lebanese group.

Israel's defense minister warned on Wednesday that the Israeli retaliation for a recent Iranian missile attack will be "lethal" and "surprising."

"Our strike will be lethal, precise and above all, surprising. They won't understand what happened and how. They will see the results," Defense Minister Yoav Gallant said during a speech to troops. "Whoever strikes us will be harmed and pay a price."

U.S. President Joe Biden and Vice President Kamala Harris held "productive" talks Wednesday with Israeli leader Benjamin Netanyahu about Israel's response to last week's missile attack by Iran, the White House said.

Hamas said on Wednesday it had begun meetings with rival Palestinian faction Fatah in Cairo to discuss the year-long war in the Gaza Strip and efforts towards national unity.

"A meeting has just commenced in the Egyptian capital, Cairo, between the delegations of the Hamas movement... and the Fatah movement," a Hamas statement read, adding that they were discussing "aggression on the Gaza Strip, the political and field developments, and to unify national efforts and ranks".

Israel has promised to retaliate for Iran's massive missile attack last week. How it does so involves great risk, and could have major repercussions for the archenemies, the Middle East and the world.

Israel's options range from symbolic strikes on military targets to crippling attacks on Iran's vital oil industry or its secretive and heavily fortified nuclear program.

At least six people were stabbed and wounded in northern Israel in what police say was a militant attack.

Police said the assailant stabbed people in multiple locations in the northern city of Hadera on Wednesday before fleeing on a motorbike. Police said they later shot and “neutralized” him, indicating he was killed. They did not provide the name or nationality of the assailant.

Israeli bombardment on Wednesday killed a policeman in the south of Syria near the Israeli-annexed Golan Heights, state media said, the day after a deadly air strike on the capital.

Israel has repeatedly struck Syria throughout the civil war that started in 2011, but it has ramped these up in recent weeks as it also pounds Lebanon.

A large-scale Israeli operation in northern Gaza has killed and wounded dozens of people and threatens to shut down three hospitals over a year into the war with Hamas, Palestinian officials and residents said Wednesday.

Heavy fighting is underway in Jabaliya, where Israeli forces carried out several major operations over the course of the war and then returned as militants regroup. The entire north, including Gaza City, has suffered heavy destruction and has been largely isolated by Israeli forces since late last year.

Iranian Foreign Minister Abbas Araghchi travelled to Saudi Arabia on Wednesday for talks that were expected to cover efforts to end fighting between the Israeli military and Iran-backed groups in Gaza and Lebanon.

"I hope that these consultations can lead to better conditions for Palestine and Lebanon and establish peace in the region," Araghchi told Iranian state television upon his arrival in Riyadh.