(UPI) — Al-Shabab, a Somali terror group linked to al-Qaeda, attacked a military base Sunday morning in Kenya that houses some American military personnel, U.S. and Kenyan military said.

Al-Shabab is a Sunni Muslim group and is not linked to Shiite Iran. Last week, a U.S. airstrike killed Iran’s top military commander and Iran vowed retaliation.

At approximately 5:30 a.m., Kenya Defense Forces said terrorists attempted to breach security at the Manda Bay Airfield, which is near the border with Somalia. “The attempted breach was successfully repulsed. Four terrorists bodies have so far been found,” the Kenyan military posted on Twitter.

U.S. Africa Commandsaid the airfield has been “cleared and still in the process of being full secured.” There was damage to the infrastructure and equipment, and a check of personnel is underway.

“U.S. Africa Command acknowledges there was an attack at Manda Bay Airfield, Kenya and is monitoring the situation,” U.S Army Maj. Gen. William Gayler said in a statement. “Al-Shabab resorts to lies, coercion, and the exertion of force to bolster their reputation to create false headlines … It is important to counter al-Shabab where they stand to prevent the spread of this cancer.”

Earlier, al-Shabab said some of its fighters had launched “a daring dawn raid on a U.S. naval base known as ‘Camp Simba’ in Lamu County, Kenya,” according to the Tasnim News Agency in Iran.

Camp Simba is near the Manda Airstrip and where Western visitors to Kenya frequently visit.

Their fighters had taken control of a portion of the base and there were “severe casualties on both American and Kenyan troops stationed there.”

AFRICOM said the group has been “exaggerating the security situation on the ground.”

No number of Americans at the base was given.

The base been a site for U.S. special operations forces operating in Somalia. About 500 U.S. troops are in Somalia to assist and advise the nation’s military against the terror group.

“Al-Shabab is a brutal terrorist organization,” Gayler said. “It is an Al-Qaeda affiliate seeking to establish a self-governed Islamic territory in East Africa, to remove Western influence and ideals from the region, and to further its jihadist agenda. U.S. presence in Africa is critically important to counter-terrorism efforts.”

Africom noted this is the same terror group killed 80 people in Mogadishu, Somalia, last week.

The Somali government and U.S. Africa Command have conducted retaliatory airstrikes on al-Shabab target recently, according to a CNN report.