A British casualty has died in a militant attack on a luxury hotel in Nairobi, according to reports.

A mortuary worker told Reuters news agency that a British man and an American woman were among 15 people killed in Kenya’s capital.

Extremist militants stormed the luxury DusitD2 hotel complex on Tuesday, setting off explosions and gunning down people.

Special forces were sent into the hotel to flush out the gunmen believed to be holed up inside.

Kenya Attack
Civilians who had been hiding in buildings flee under the direction of a member of security forces (Ben Curtis/AP)

The area includes bars, restaurants, offices and banks and is popular with many American, European and Indian expatriates.

Al-Shabab — the Somalia-based group that carried out the 2013 Westgate Mall attack in Nairobi that left 67 people dead — has claimed responsibility.

A Foreign Office spokeswoman said: “The situation is ongoing. We are in contact with the Kenyan authorities who are coordinating a response and stand ready to assist as required.”

Late on Tuesday night, Interior Minister Fred Matian’i said that all of the buildings affected by the attack had been secured.

He did not give a toll of the dead and wounded, and the number of attackers was not clear.