The US embassy has issued a security alert to its citizens in Kenya, warning of planned attacks by extremists in Nairobi.

The alert, which was issued on Monday 4,  urges US citizens particularly in Nairobi, Naivasha, Nanyuki, and coastal regions to exercise caution especially in public spaces such as shopping malls, hotels, and places of worship.

“Credible information indicates Westerners may be targeted by extremists in Nairobi, Naivasha, Nanyuki, and coastal areas of Kenya. Be aware of your surroundings, and report suspicious activity to authorities immediately,” the alert reads in part.

The alert further recommends that U.S. citizens traveling to or residing in Nairobi enroll in the Department of State’s Smart Traveler Enrollment Program (STEP), which gives the latest security updates and makes it easier for the embassy or nearest U.S. consulate to contact them in case of an emergency.

The US security alert comes a week after terrorists attacked an upmarket hotel, Dusit D2 in Nairobi’s Riverside drive, killing 21 people.

US citizen Jason Spindler, CEO of I – DEV, is among those who died during the attack. His family said he was a survivor of the 9-11 US attack.