An Israeli air strike hit an apartment building in northern Lebanon on Monday, killing at least 18 people, according to the Lebanese Red Cross.

There was no immediate comment from the Israeli military, and it was not clear what the strike's intended target had been.

The strike hit a small apartment building in the village of Aitou, far from the Hezbollah militant group's main strongholds in the south and east of the country.

Hours earlier, an Israeli air strike on a hospital courtyard in the Gaza Strip killed at least four people and triggered a fire that swept through a tent camp for people displaced by the war, leaving more than two dozen with severe burns, according to Palestinian medics.

The Israeli military said it targeted militants hiding out among civilians, without providing evidence.

In recent months it has repeatedly struck crowded shelters and tent camps, alleging that Hamas fighters were using them as staging grounds for attacks.

Al-Aqsa Martyrs Hospital in the central city of Deir al-Balah was already struggling to treat a large number of wounded from an earlier strike on a school-turned-shelter that killed at least 20 people when the early morning air strike hit and fire engulfed many of the tents.

Several secondary explosions could be heard after the initial strike, but it was not immediately clear if they were caused by weapons or fuel tanks.

Associated Press footage showed children among the wounded. A man sobbed as he carried a toddler with a bandaged head in his arms.

Another small child with a bandaged leg was given a blood transfusion on the floor of the packed hospital.

Further Israeli air strikes on a northern Gaza food distribution centre killed 10 people and injured at least 30 also on Monday, Palestinian medics said.

Medics said the casualties at the food distribution centre in the Jabalia refugee camp in northern Gaza included women and children.

The IDF has yet to comment.

Australians told 'do not travel' to Israel

The Australian government has raised its travel warning for Israel to Do Not Travel, flagging an ongoing threat of missile and rocket attacks.

Minister for Foreign Affairs Penny Wong said in a statement on X the government had "serious concerns the security situation" in the region could deteriorate rapidly.

Warnings are already in place against travelling to the Occupied Palestinian territories, Lebanon, Iran and some other nearby countries.

The latest advice to Australians in Israel is to leave while commercial flights remain available and border crossings are open.

EU responds to Israeli 'attacks' on peacekeepers

The strikes came as the European Union issued a response to United Nations Interim Force in Lebanon (UNIFIL) reports that its peacekeepers had been injured under fire from the IDF.

"Such attacks against UN peacekeepers constitute a grave violation of international law and are totally unacceptable. These attacks must stop immediately," EU foreign policy chief Josep Borrell said in a statement on behalf of the union published on Sunday night.

EU countries have thousands of troops in the 10,000-strong peacekeeping mission in southern Lebanon, which has said it has repeatedly come under attack from Israeli forces in recent days.

"The EU condemns all attacks against UN missions," Mr Borrell said.

"It expresses particularly grave concern regarding the attacks by the Israel Defense Forces against UNIFIL, which left several peacekeepers wounded."

Mr Borrell said "all actors" in the conflict had the obligation to ensure the safety and security of UN personnel and property.

"We urgently await explanations and a thorough investigation from the Israeli authorities about the attacks against UNIFIL, which plays a fundamental role in the stability of South Lebanon."

In an EU ministerial meeting in Luxembourg on Monday, he added that EU nations took too long to condemn the IDF's "completely unacceptable" actions.

"We should be against Israeli attacks against UNIFIL. Our soldiers are there, many soldiers are there," he said.

Spain's Foreign Minister José Manuel Albares told reporters ahead of the meeting that the IDF's actions were "unacceptable" and contrary to UN rules.

Israel has disputed some UN accounts of incidents involving UNIFIL peacekeepers in Lebanon, and Prime Minister Benjamin Netanyahu said the peacekeepers were providing "human shields" for Hezbollah militants during an upsurge in hostilities.

Hezbollah targets Haifa naval base, clashes with IDF in Lebanon

Hezbollah said it targeted an Israeli naval base near north Israel's Haifa on Monday, a day after claiming a drone attack near the city that the Israeli military said killed four soldiers.

The IDF confirmed that sirens were previously blaring around Haifa.

Hezbollah fighters launched "a rocket salvo" at the Stella Maris naval base near Haifa, the Lebanese group said in a statement, adding the attack was at the "service" of Hassan Nasrallah — the group's longtime leader who was killed in an Israeli strike on Beirut's southern suburbs last month.

The group, which is listed as a terrorist organisation by Australia, also said it shelled Israeli troops inside a south Lebanon village on Monday, after earlier saying it targeted Israeli soldiers elsewhere along the border.

Hezbollah fighters targeted "a gathering of Israeli enemy soldiers in the south of Maroun al-Ras with artillery shells", a statement read.

ABC/wires