"Fifteen people were martyred and more than 20 were injured in this massacre after midnight in a house where displaced people were living in the town of Jabalia," civil defence agency's spokesman Mahmud Bassal told AFP. The Israeli military, when contacted, said it was looking into the reported strike.

Bassal said that those living in the house were members of the Badra, Abu Warda, and Taroush families who had sought refuge there.

Most of Gaza's 2.4 million people have been displaced at least once since the start of the war on October 7 last year.

Since October 6, the Israeli military has been conducting a major land and air offensive in northern Gaza, particularly targeting the city of Jabalia and its adjacent refugee camp, in what it described as an effort to prevent Hamas militants from regrouping there.

The assault has since been expanded across the northern areas of the Palestinian territory and last week targeted a major hospital which is now empty of its staff and patients.

On Friday, the Israeli military raided the Kamal Adwan Hospital in Beit Lahia, describing it as "one of the largest" operations targeting militants since the start of the war.

The military said it killed more than 20 militants and detained over 240 others, including the director of the hospital, who it claims, is a suspected Hamas militant.

Rights groups and the World Health Organisation have called for the immediate release of Hossam Abu Safiyeh, whose detention is seen as a blow to the territory's devastated healthcare system.