The U.S. Embassy in Nairobi is warning that an imminent terrorist attack in Kenya is possible.

The warning was sent out Saturday to all U.S. citizens in the African country, citing credible information. It says that likely targets include places where foreigners gather, including shopping malls and night clubs.

U.S. officials did not specify who might carry out such an attack, but the warning comes a week after Kenyan troops pushed into Somalia to attack al-Shabab militants.

Kenyan troops crossed the Somali border to oust the militants who they say have taken several foreigners hostage in recent weeks.

The Somalian-based terrorist group carried out attacks in July in Uganda which killed 76 people.