samantha-lewthwaite-1-522x293A British woman and “two or three Americans” are among the militants who took part in an attack on a shopping centre in Nairobi.

Kenyan Foreign Minister Amina Mohamed confirmed al Shabaab fighters were responsible for the attack.

In an interview with the PBS Newshour programme, Ms Mohamed said: “Both the victims and the perpetrators … came from Kenya, the United Kingdom and the United States.

“From the information that we have, (there are) two or three Americans, and I think so far I have heard of one Brit.”

Asked about the British woman, Ms Mohamed added: “A woman, woman, and I think she has done this many times before.”

The announcement will fuel speculation that British terror suspect Samantha Lewthwaite, who was married to the July 7 bomber Jermaine Lindsay, was involved in the Kenya attack.

Ms Lewthwaite, dubbed the “White Widow”, is known to be in East Africa and is wanted by Kenyan police over alleged links to a terrorist cell that planned to bomb the country’s coast.

In March last year officials said she had fled to Somalia and that officers were hunting a woman who used several identities, including hers.

On Monday night, Ms Lewthwaite’s grandmother, Elizabeth Allen, 86, of County Down in Northern Ireland, was said by a friend to be “deeply distressed” by suggestions her granddaughter had been involved in the attack.

Ms Lewthwaite has gained “semi-mythical status” since travelling to East Africa, according to terrorism expert, Raffaello Pantucci, a senior research fellow at the Royal United Services Institute.

Mr Pantucci said: “There has been a lot of speculation about it. Samantha Lewthwaite, since she appeared in East Africa, has been elevated in some ways to a semi-mythical status.

“I don’t think we’ve had any concrete evidence of her being involved in this incident, but the fact of her being mentioned in this context is not surprising because of her connections, and it is known that she is somewhere in East Africa.”

A spokesperson for the Foreign Office said: “Aware of the Foreign Minister’s comment, we continue to liaise very closely with the Kenyan authorities and to support their investigation into this attack.

“The UK will do everything it can to support the Kenyans bringing everyone responsible for this vicious attack to justice.”

Ms Mohamed said the Americans involved in the shopping centre attack are aged about 18 or 19 years.

“The Americans, from the information that we have, are young men. About between 18 and 19, of Somali origin or Arab origin, but … lived in the US in Minnesota and one other place,” she said.

“I think that just goes to underline the global nature of the war that we’re fighting.”

FBI sources are investigating claims that the terrorists involved in the attack were recruited in the Midwest in a Somali community known as “Little Mogadishu” in Minneapolis, according to The Times.

Somalia’s al Qaeda-linked al Shabaab group has claimed responsibility for the attack, which began on Saturday.

Kenyan security forces claim they have taken control of the shopping centre after a final assault on the militants, however, heavy gunfire can still be heard coming from the complex.

Some security sources say some of the terrorists could still be hiding.