An Israeli air strike on a compound in the northern Gaza Strip has killed one Palestinian and wounded at least three others, doctors say.
Palestinian medical officials said that the strike late on Sunday night targeted a naval base used by Hamas, killing a policeman.
The mayor of Beit Lahiya, Izzedine Dahnoun, said an electricity transformer supplying northern Gaza from Israel was damaged by the blast, knocking out power to some 100,000 people.
The Israeli military said the air strike "hit a terror activity centre in the northern Gaza Strip" after a rocket was fired into Israel hours earlier, causing no injuries.
The rocket had been fired into the Shaar Hanegev area of southern Israel, north of Gaza, the Israeli military said.
Israel has said that it holds Hamas responsible for any cross-border rockets fired into its territory.