A Palestinian health official said Wednesday that at least 21 people were killed by an Israeli strike on a camp housing displaced people in Gaza. Atif Al-Hout, the director of Nasser Hospital in the southern city of Khan Younis, said at least 28 people were wounded in the strike.

The Israeli military said its aircraft struck senior Hamas militants “involved in terrorist activities” in the area. The military said that the strike had set off secondary explosions, indicating explosives present in the area were set off. It was not possible to independently confirm the Israeli claims, and the strike could also have ignited fuel, cooking gas canisters or other materials in the camp.