Israeli strikes killed at least 17 people in Gaza City on Saturday, Palestinian emergency workers said, a day after Israel ended a policy of pausing its attacks in the area for several hours daily to facilitate the delivery of humanitarian relief.

One of the attacks targeted a “key” Hamas figure, the Israeli military said in a statement. According to three Israeli officials, the strike targeted Abu Obeida, the spokesman for the Qassam Brigades, Hamas’s armed wing. All three spoke on condition of anonymity to discuss the sensitive subject.

It was not immediately clear whether Israel had succeeded in killing Abu Obeida, which is a nom de guerre. Mr. Obeida frequently appears, masked and defiant, in videos disseminated by Hamas, making him one of the group’s best-known representatives in the Arab world.

At least five people were killed in the attack, which took place in the Rimal neighborhood of Gaza City, according to the Palestinian Civil Defense rescue service.

In a separate strike near a bakery, an additional 12 people were killed, said Mohammad Abu Salmiya, the director of the city’s Al Shifa hospital.

Neither toll could be independently verified. The Israeli military did not immediately respond to a request for comment on the second strike.