Israeli aircraft attacked militant targets in the Gaza Strip on Tuesday in retaliation for a rocket fired into the western Negev late Monday night, the military said in a statement.

The targets were an underground rocket launcher in central Gaza and "a terror site" in northern Gaza, the statement said, adding that direct hits were confirmed.

The strike came hours after a rocket exploded in an open area near the coastal city of Ashkelon, the latest in a string of cross border rocket attacks on southern Israel in recent months. No injuries or damage were reported on the Israeli side.

Lt. Col. Peter Lerner, a military spokesman, said in the statement that Israel views Islamist group Hamas, which rules Gaza, as accountable for allowing the rocket fire to continue unabated.