NAIROBI (Dispatches) -- Militants from Somalia's Al-Shabaab group on Sunday stormed a military base used by U.S. forces in Kenya's coastal Lamu region, killing three Americans and destroying several aircraft and military vehicles, officials said.
Attackers breached heavy security at Camp Simba at dawn but were pushed back and four militants killed, said army spokesman Colonel Paul Njuguna.
The U.S. military, however, said three Americans died in the attack including a service member and two military contractors.
Two other Pentagon personnel were wounded, the statement added, without giving further details.
Al-Shabaab has launched regular cross-border raids since Kenya sent troops into Somalia in 2011 as part of an African Union force protecting the internationally backed government -- which the militants have been trying to overthrow for more than a decade.
The Lamu region, which includes popular tourist beach destination Lamu Island, lies close to the Somali frontier and has suffered frequent attacks, often carried out with roadside bombs.
Kenya's Inspector General of Police Hilary Mutyambai said officers were "on high alert" after the attack.
An internal police report seen by AFP said two Cessna aircraft, two American helicopters and "multiple American vehicles" were destroyed at the airstrip.
Shabaab claimed to have killed 17 Americans and nine Kenyan soldiers after the attack.
The nearby airport at Manda Bay, which brings tourists visiting Lamu Island -- a UNESCO World Heritage Site -- was closed for several hours after the incident, according to the civil aviation authority.
Al-Shabaab said in a statement it had "successfully stormed the heavily fortified military base and have now taken effective control of part of the base".
AFRICOM accused Al-Shabaab of lying in order to create false headlines.
Shabaab countered with a second statement, saying it had been a 10-hour firefight and mocking the U.S. inability to fend off an attack by just a handful of men.
The group referred to an uptick in U.S. military airstrikes under President Donald Trump, accusing the U.S. of "strafing villages from above and indiscriminately bombarding innocent women and children."
AFRICOM said in April it had killed more than 800 people in 110 strikes in Somalia since April 2017.
The Somali militants have staged several large-scale attacks inside Kenya in retaliation for Nairobi sending troops into Somalia as well as to target foreign interests.
The group has been fighting to overthrow the government in Mogadishu since 2006, staging regular attacks on government buildings, hotels, security checkpoints and military bases in the country