The chief of Gaza's Hamas-run police force and his deputy have been killed in an Israeli strike on a tent camp sheltering displaced families.

The Hamas-run interior ministry condemned what it called the "assassination" of Mahmoud Salah and Hussam Shahwan, who it said had been "performing their humanitarian and national duty".

Nine other people, including three children and two women, were also killed in the overnight attack in al-Mawasi, near the southern city of Khan Younis, medics said.

Israel's military confirmed it had carried out a strike targeting Shahwan, who it alleged was a "terrorist" who had helped Hamas's military wing plan attacks on Israeli forces in Gaza.

More than 30 people were reportedly killed in other Israeli strikes across Gaza on Thursday, while the military said it intercepted a projectile fired from the south of the territory.

The Gaza interior ministry accused Israel of "spreading chaos" and "deepening the human suffering" in the territory by killing Salah and Shahwan. It insisted that the police force was a "civilian protection agency" that provided services to Palestinians.

There has been increased lawlessness in Gaza since Israel began targeting police officers last year, citing their role in Hamas governance.

The Israel Defense Forces (IDF) said the police force had "conducted violent interrogations of the Gazan population, violating human rights and suppressing dissent".

"Hassam Shahwan was responsible for developing intelligence assessments in coordination with elements of Hamas's military wing in attacks on the IDF in the Gaza Strip," it alleged.

The military also said it had taken "numerous steps" to mitigate the risk of harming civilians prior to the strike on al-Mawasi.

Three brothers aged seven, 11 and 13 were among the nine other people who were killed.

Ahmed, Mohammed and Abdul Rahman al-Bardawil were hit by shrapnel as they slept in their family's tent, their father Walid said.

"I woke up to the sound of the explosion. I called my three sleeping sons, but no-one answered. They were martyred immediately," he told AFP news agency.

Social media videos showed the boys' bodies being transported to a local hospital by a tuk-tuk, as well as their blood-stained mattresses inside a damaged tent.

Aida Zanoun, who was living in a neighbouring tent, said she heard an Apache helicopter gunship flying overhead at around 01:00 (23:00 GMT Wednesday).

"Then we saw a very strong [explosion]. It caused an earthquake in the neighbourhood. The shrapnel reached as far as 100m [330ft], they say," she told Reuters news agency.

"When the morning came, we came to inspect [the scene], and... it is devastation, complete destruction. What have the children done, to be hit?"

The IDF has declared the sandy strip of land along the coast in al-Mawasi to be a "humanitarian zone" for the hundreds of thousands of Palestinians displaced by its 14-month war with Hamas.

But it has repeatedly attacked the area, accusing Hamas operatives of hiding among civilians.

Later, another six people were killed in an Israeli air strike at the Gaza interior ministry's headquarters in Khan Younis, medics said.

The IDF said it had conducted a strike on "Hamas terrorists who were operating in a control-and-command centre that was embedded inside the Khan Younis municipality building".

Palestinian media reported that at least 30 people were killed in Israeli strikes elsewhere in Gaza on Thursday.

Ten were killed in the northern town of Jabalia, which is besieged by Israeli ground forces, while four were killed in Shati refugee camp to the west, according to the Palestinian Wafa news agency. Twelve others died at two intersections in nearby Gaza City, it said.

Four people were killed in the central town of Deir al-Balah and several others were killed in nearby Maghazi refugee camp, Wafa added.

Meanwhile, recent cold, wet weather has worsened conditions in makeshift camps for displaced families.

More than 1,500 tents across Gaza have been flooded by rainwater and sewage since Tuesday, according to the Hamas-run Civil Defence agency.

"When we woke up... we were shocked to find that the rain had flooded [our tent], causing us to be submerged in sewage," Moataz Abu Hatab told BBC Arabic's Gaza Today programme.

"Everything we had - our mattresses, blankets, and clothes - was lost. All the items we had managed to buy or receive during the war are now gone, and we are left with nothing."

Israel launched a campaign to destroy Hamas in response to the group's unprecedented attack on southern Israel on 7 October 2023, in which about 1,200 people were killed and 251 others were taken hostage.

More than 45,580 people have been killed in Gaza since then, according to the territory's Hamas-run health ministry.