At least 16 people were killed in an Israeli strike on a school sheltering displaced Palestinian families in central Gaza on Saturday, the Palestinian health ministry said, in an attack Israel said had targeted militants.

The health ministry said the attack on the school in Al-Nuseirat killed at least 16 people and wounded more than 50.

The Israeli military said it took precautions to minimize risk to civilians before it targeted the gunmen who were using the area as a hideout to plan and carry out attacks against soldiers. Hamas denied its fighters were there.

At the scene, Ayman al-Atouneh said he saw children among the dead. “We came here running to see the targeted area, we saw bodies of children, in pieces, this is a playground, there was a trampoline here, there were swing-sets, and vendors,” he said.

Mahmoud Basal, spokesman of the Gaza Civil Emergency Service, said in a statement that the number of dead could rise because many of the wounded were in critical condition.

The attack meant no place in the enclave was safe for families who leave their houses to seek shelters, he said.