At least 40 Palestinians were killed in an Israeli air strike on a tent encampment in Khan Younis in the southern Gaza Strip, medics and Hamas media said early on Tuesday, as the Israeli military said it targeted a Hamas command centre.

Residents and medics said a tent encampment in the Al-Mawasi area, which is designated as a humanitarian zone, was struck by at least four missiles. 

The camp is crowded with displaced Palestinians who have fled from elsewhere in the enclave.

Gaza civil defence official Mohammed Al-Mughair told AFP early on Tuesday that "40 martyrs and 60 injured were recovered and transferred" to nearby hospitals following the overnight strike.

"Our crews are still working to recover 15 missing people as a result of targeting the tents of the displaced in Mawasi, Khan Younis," Mughair added.

In a separate statement, civil defence spokesman Mahmoud Basal said that people sheltering in the camp had not been warned of the strike, adding a shortage of tools and equipment was hindering rescue operations.

"More than 20 to 40 tents were completely damaged," he said, adding the strike left behind "three deep craters".

The Israeli military said in a statement early Tuesday that its aircraft had struck a Hamas command centre embedded inside the camp.

There was no immediate comment from the Gaza health ministry, which compiles casualty figures. 

Ambulances raced between the tent camp and a nearby hospital, while Israeli jets could still be heard overhead, residents said.

Nearly all of Gaza's 2.3 million people have been forced from their homes at least once, and some have had to flee as many as 10 times.

The war was triggered on October 7 when Hamas attacked Israel, killing 1,200 and taking about 250 hostages, according to Israeli tallies. 

Israel's subsequent assault and invasion of Gaza has killed more than 40,900 Palestinians, according to the enclave's health ministry.

Detained UN convoy released by IDF

The Israeli military released a convoy of UN staff held for hours in northern Gaza, the head of the UN agency for Palestinian refugees said on Monday.

"The Israeli army stopped a UN convoy on its way to northern Gaza for more than eight hours today (Monday) despite prior detailed coordination," the UNRWA commissioner-general Philippe Lazarrini wrote in a statement on X.

Mr Lazarrini said the vehicle convoy included Palestinian and international staff working as part of the polio vaccination campaign underway in northern Gaza and Gaza City. 

The UN is working to vaccinate 640,000 children against the virus which re-emerged in the occupied territory in August.

The Israeli military said on Monday it detained the convoy after receiving intelligence indicating that a number of "Palestinian suspects" were travelling with the convoy and that it wanted to question them.

"The convoy was stopped at gun point just after the Wadi Gaza checkpoint with threats to detain UN staff," Mr Lazzarini said. 

"All staff & convoy are now released & back safely in the UN base," he said.

The commissioner-general said the incident was the latest in a number of shootings and arrests of UN staff in the occupied territory by the Israeli Defense Forces (IDF). 

The UN's World Food Programme temporarily suspended staff movement in Gaza in late August after a team came under fire near an Israeli checkpoint outside of Gaza City. 

Australian aid worker Zomi Frankcom was killed in Gaza in April when a World Central Kitchen convoy she was travelling in came under Israeli fire.

A report by appointed special advisor Mark Binskin said "serious" failures by the Israeli military led to Ms Frankcom's death. 

US calls for investigation into US-Turkish citizen killed in West Bank

A march to honour US-Turkish citizen Aysenur Ezgi Eygi was held in the West Bank on Monday, with hundreds of people lining the streets of Nablus. 

Ms Eygi's body was carried by members of the Palestinian security forces, wrapped in a Palestinian flag and keffiyeh as mourners held up photos of her. 

Turkish and Palestinian officials said on Friday that Israeli troops shot the 26-year-old, who had been taking part in a protest against settlement expansion in the West Bank.

"Our understanding is that our partners in Israel are looking into the circumstances of what happened, and we expect them to make their findings public, and expect that whatever those findings are, expect them to be thorough and transparent," US State Department deputy spokesperson Vedant Patel told a news briefing.

White House national security spokesperson John Kirby later said Israel was understood to be "moving swiftly on this investigation" and was expected to present its findings and conclusions in the coming days.

Turkey's President Tayyip Erdogan condemned Ms Eygi's death, saying in a post on social media that Turkey "will continue to work in every platform to halt Israel's policy of occupation and genocide". 

Israel denies its actions in occupied Palestinian territories amount to genocide.

A rise in violent attacks by Israeli settlers on Palestinians in the West Bank has stirred anger among Western allies of Israel, including the United States, which has imposed sanctions on some Israelis involved in the settler movement.