The five-star Hilton, Nicon Luxury and Sheraton hotels in Nigeria’s capital, which are frequented by diplomats, politicians and Nigeria’s business elite, were identified by the US embassy.

In an unusually specific warning on Sunday, US diplomats have advised their staff to avoid luxury hotels in Abuja. The embassy said the attack may come as Nigeria celebrates the Muslim holiday Eid al-Adha. Experts say the militant Islamist group Boko Haram, which claimed responsibility for Friday’s violence and threatened more attacks, is working with al Qaeda which could push Nigeria into a Somalia-style civil war.