The United States on Tuesday warned of possible attacks against expatriates and foreign visitors in Lagos, during public holidays marking the end of the Muslim holy month of Ramadan.

“The US Mission in Nigeria advises that groups associated with terrorist activity might be planning attacks against hotels in Lagos frequented by international visitors, including those located on waterfronts, during the Eid-al-Fitr holidays,” it said.

Tuesday and Wednesday are public holidays in Nigeria and the traditional end of a month of fasting and prayer is marked by celebrations across the country.

The US warning, posted on its embassy’s website, is unusually specific but not the first about possible attacks in locations frequented by expatriates.

A similar security warning was given in December last year, while in May 2014 diplomats warned of a possible attack at two Sheraton hotels in Lagos, after a car bombing in the capital, Abuja, killed 19 just days before a major economic summit.

Similar warnings were given in April 2012 and November 2011 about hotels popular with Westerners in Abuja.

Lagos, a melting pot megacity of some 20 million people, has been spared the worst excesses of violence by the Islamist group Boko Haram, whose seven-year insurgency has destroyed Nigeria’s northeast.

But the southwestern coastal city has been hit before. On June 25, 2014, explosions ripped through the port area near a major fuel depot.

The authorities blamed the blast on a cooking gas cylinder which exploded but eyewitnesses and Western diplomats said it was a car bomb that killed at least four people.

Boko Haram’s shadowy leader Abubakar Shekau later claimed responsibility.

The US Embassy’s latest warning did not mention a specific group but urged its citizens to “review your personal security plans, remain aware of your surroundings, including local events, and monitor local news stations for updates.”

•Text courtesy of The Guardian. Photo shows Boko Haram leader Abubakar Shekau.