CNN has cited a U.S. military official as saying that a North Korean torpedo attack was the most likely cause for the sinking of South Korea’s “Cheonan” warship last month.

The official says the U.S. believes the ship was sunk by the blast of an underwater explosion, but that the explosive device itself did not come in contact with the hull of the ship.

The report noted that this is the same conclusion expressed by South Korean military officials.