Islamist militant group al-Shabab has killed one US service member and two US contractors in an attack on a base in Kenya, the US Military has said.
Witnesses reported hearing gunfire and seeing plumes of black smoke emerge from Camp Simba on Manda Island.
Kenya's military said the insurgents had been driven out of the base, but the US Africa Command said the security situation remained "fluid".
Al-Shabab is linked to al-Qaeda and is headquartered in neighbouring Somalia.
In a statement, the US military said two military contractors and a US service member had been killed in the attack, and two Department of Defence staff were injured.
The injured staffers were being evacuated in a stable condition, the statement said.
The group has carried out a spate of attacks in the region since it was formed more than a decade ago.
On 28 December, about 80 people were killed in a bombing in Somalia's capital, Mogadishu.
What happened at Camp Simba?
The Kenyan Defence Forces (KDF) said "an attempt was made to breach security at Manda Air Strip" but the attack was repulsed.
Four militants were killed, it said.
A fire caused by the attack had been extinguished and the airstrip was now safe, a KDF spokesman said.
A nearby airfield used for civilian flights had reopened, aviation officials said.
Al-Shabab said it had "successfully stormed the heavily fortified military base" before taking "effective control of a part of the base".
The group said the Kenyan military used warplanes to repel the attack.
How extensive was the damage?
The Associated Press news agency reported that two aircraft, two US helicopters and multiple vehicles were destroyed at the airstrip.
Al-Shabab said it had killed nine Kenyan soldiers and had inflicted 17 "battle casualties" on US forces.
Seven aircraft and five military vehicles had been destroyed, it added.
A journalist with Voice of Africa tweeted photos of what the militants said was a US aircraft that had been targeted.
In a statement, the US Africa Command said the airfield was still in the process of being "fully secured".
"Initial reports reflect damage to infrastructure and equipment. An accountability of personnel assessment is under way," the statement added.
The camp has fewer than 100 US personnel, AP reported.
This was the first attack by al-Shabab on US forces in Kenya.
In June 2018, a US commando was killed in Somalia during an attack by al-Shabab.
The US has stepped up military operations against the militants since Donald Trump became president in 2017.
The US military conducted more air strikes in Somalia in 2019 than in any previous year.
- BBC / Reuters