Updated

The U.S. warned its citizens Wednesday that a radical Islamist sect may attack hotels frequented by foreigners in Nigeria's capital, the second time it has advised such an assault is possible in the widening sectarian fight in the West African nation.

The warning offered no specifics about the threat posed by the sect known as Boko Haram, only saying that the Nigerian government was aware and taking precautions to stop such an assault. The United Kingdom also issued an advisory to its citizens Wednesday noting the U.S. message, saying its "existing travel advice is consistent with this warning."

Deb MacLean, a spokeswoman with the U.S. Embassy, said she could not offer any other information about the warning. However, she said U.S. officials spoke with the Nigerian government before issuing the alert. A similar alert issued in November angered Nigerian officials.

Early Wednesday morning, an Associated Press journalist in Abuja only saw private security guards checking cars at the major hotels in the capital. Most opened the trunks of cars and looked at vehicles' undercarriages with mirrors on telescoping poles. However, at the Sheraton, private guards appeared to be using a hand-held explosive detector when walking around vehicles.

The National Assembly also appeared to have more police officers guarding it Wednesday morning.

The U.S. issued a similar warning in November after Boko Haram launched an attack in the northeastern state of Yobe that killed more than 100 people. That warning specifically mentioned the capital's Hilton, Nicon Luxury and Sheraton hotels. With popular restaurants and bars, the hotels draw diplomats, politicians and even reformed oil delta militants.

It wouldn't be the first time Abuja saw itself targeted by Boko Haram, which has waged an increasingly bloody sectarian fight against Nigeria's weak central government. A suicide bomber claimed by Boko Haram attacked the United Nations headquarters in Abuja in August, killing 25 people and wounding more than 100 others. Another Boko Haram bomber targeted the federal police headquarters in June.

Still, most attacks have targeted Nigeria's arid and impoverished north, so any strike against hotels in Abuja would be an escalation that shows the group's ability to strike at will, even against foreigners and its elite.

Boko Haram, whose name means "Western education is sacrilege" in the Hausa language of Nigeria's north, is blamed for killing more than 430 people this year alone in Nigeria. The sect has rejected efforts to begin indirect peace talks with Nigeria's government. Its demands include the introduction of strict Shariah law across the country, even in Christian areas, and the release of all imprisoned followers.