The U.S. carried out nine drone strikes between September 23 and December 13, CENTCOM confirmed Thursday. The strikes targeted members of al-Qaeda in the Arabian Peninsula and were said to have killed 28 members of the group. The press release did not disclose whether any civilians had been killed or hurt in the strikes. The U.S. has come over scrutiny for its increased involvement in a military campaign in Yemen, which has been embroiled in sectarian warfare since 2014. In October, the U.S. directly entered the conflict for the first time, sending a warship to fire on radars in Houthi rebel territory, after the rebel group was believed to have targeted a U.S. ship in two failed missile strikes. The Houthi group denied their involvement in the attempted strikes.