SANAA, Yemen — A series of U.S. airstrikes targeted alleged al-Qaida positions on Thursday in a mountainous area where three Yemeni provinces meet, leaving at least four militants dead, Yemeni officials said.

The officials told The Associated Press that U.S. jets and drones targeted at least six districts and they were all located in a mountainous area where the three provinces of Bayda, Shabwa and Abyan meet. The vast region is known for its rocky mountains, which have been used by al-Qaida as a hideout.

One media official in Bayda said a total of 23 airstrikes were carried out by U.S. jets. Another official said four al-Qaida militants were killed in the airstrikes that targeted Shabwa’s Saeed district.

The bombings took place between 2 a.m. and 5 a.m., shaking houses and causing panic among sleeping residents who fled in fear, while smoke billowed into the sky and flashes of light were seen from a distance because of the explosions.

The Yemeni officials spoke on condition of anonymity because they weren’t authorized to speak to the media.

U.S. military officials were not immediately available for comment.