Via ABC News:

“Two or three Americans” participated in the attack on the Westgate Mall in Nairobi that has left at least 62 people dead and 175 injured, Kenyan Foreign Minister Amina Mohamed said. The Americans, aged between 18 and 19, of Somali or Arab origin, lived in Minnesota and one other place in the U.S, she said in an interview with PBS’ NewsHour.

A British woman was also among the alleged perpetrators tied to al-Shabab, the al Qaeda-linked rebel group that launched the attack on the upscale mall Saturday, Mohamed told PBS Newshour late Monday night.

She is the first official to allege publicly that U.S. nationals were involved in the attack. The FBI says it has been unable to verify that, and other Kenyan officials have said no women were involved, only men dressed as women. The FBI is preparing to deploy a full team to Nairobi to investigate the Westgate Mall terror attack, officials told ABC News. Agents are coming from a variety of places but the case is being led by the New York field office, which handles crimes against Americans that occur in Africa.

The FBI investigates crimes against Americans and U.S. interests overseas. The United States offered assistance to the Kenyan government soon after the assault began Saturday. Meanwhile, Kenyan authorities have claimed “full control” of the Westgate Mall in Nairobi as they sweep the shopping center for any remaining terrorists, hostages still in hiding and dead bodies.

“The West Gate Mall is under the full control of gov’t forces and we are carrying out a sweep to ensure its safe for everyone,” Kenyan police tweeted today on their official Twitter account.

U.S. officials estimate that as many as 50 Americans have been recruited to al-Shabab in the past six years, with more than half traced back to Minnesota’s growing Somali community.