Israeli aircraft attacked the office of Palestinian Prime Minister Ismail Haniyeh of Hamas in Gaza City early on Sunday, witnesses said, setting the building on fire.
One bystander was slightly injured, hospital officials said. The Israeli army confirmed it attacked Haniyeh's office.
Witnesses said two missiles hit the south side of the building, setting it ablaze. Because of the late hour - 1.45 am local time, the building was empty, they said.
On Thursday, Israeli planes attacked the Interior Ministry, part of Israel's campaign to force release of a soldier abducted by Palestinian militants last Sunday.