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, reports BBC.
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.
There were also reports of other deadly Israeli strikes across Gaza on Thursday, and 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 asleep in their tent when the strike happened, their father Walid said in an interview with a local journalist.