An attack from al-Shabab militants in Manda Bay, Kenya, early Sunday left one U.S. service member and two Department of Defense contractors dead, according to U.S. Africa Command. Two other Department of Defense contractors were injured in the attack, but are listed in stable condition.

The predawn attack involving indirect and small-arms fire by the al-Shabaab extremist group was repelled and four attackers were killed.

The attempt was made to breach security at the Manda Air Strip at approximately 5.30 a.m. local time. Military Times reported, in addition to the causalities, “two fixed-wing aircraft, a U.S. Cessna and a Kenyan one, were destroyed and several U.S. vehicles at the Manda Bay military airstrip.”

“Our thoughts and prayers are with the families and friends of our teammates who lost their lives today,” said U.S. Army Gen. Stephen Townsend, commander of U.S. Africa Command, in a statement Sunday afternoon. “As we honor their sacrifice, let’s also harden our resolve. Alongside our African and international partners, we will pursue those responsible for this attack and al-Shabaab who seeks to harm Americans and U.S. interests.”

Air Force Col. Christopher Karns said the attack is not linked to tensions between the U.S. and Iran. “Al-Shabaab very much has its own agenda and seeks to attack U.S., African, and Western interests,” he said.