GAZA CITY, Gaza Strip — A U.N. official in the Gaza Strip said today Israeli forces have fired on a truck on a U.N. aid mission and killed the driver.

U.N. spokesman Adnan Abu Hasna said the incident took place during a lull declared by Israel to allow humanitarian aid to enter the territory.

He said the U.N. coordinated the delivery with Israel and that the vehicle was marked with a U.N. flag and insignia when it was shot in northern Gaza.

The Israeli army said it was investigating.

Earlier this week, an Israeli attack near a U.N. school killed more than 30 people. At the time, Israel said it opened fire after militants hiding in the crowd shot mortar shells at Israeli troops.