Nigeria's national security adviser on Monday dismissed a warning from the United States of an Islamist bomb threat to luxury hotels in the capital as not news, and said it was spreading unnecessary panic.

The U.S. embassy issued a warning to citizens on Sunday to avoid three luxury hotels in Abuja, which it said could be targeted this week, after Islamist militants killed at least 65 people in coordinated gun and bomb attacks in the northern city of Damaturu on Friday.

The attacks were the deadliest since Islamist sect Boko Haram launched an insurgency against the government in 2009. The group claimed responsibility for the violence, which left bodies littering the streets and police stations in ruins.

The (U.S. statement) is eliciting unhealthy public anxiety and generating avoidable tension, said Owoeye Andrew Azazi, Nigeria's National Security Adviser. The ... government wants to advise members of the public that it (will) continue to ensure security of lives and property under its jurisdiction.

The U.S. embassy said it had received information that Boko Haram may plan to attack several locations and hotels in Abuja, this week and that targets may include the Nicon Luxury, the Sheraton Hotel, and the Transcorp Hilton Hotel.

Azazi dismissed this as old information. The hotels are seen as one of the most obvious targets for Boko Haram, a militant group self styled on the Taliban whose name means Western education is forbidden.

Rumours they could be targeted are often circulated.

The current threat of attack on the three hotels in Abuja is not news, and for over three months the security services have taken pro-active measures, Azazi said. Members of the public are ... urged to go about their business without fear.

A U.S. embassy spokesman contacted by Reuters declined to comment further.

Boko Haram appears to be growing in boldness and sophistication and security officials believe it has made contact with al Qaeda's north African affiliate.

Nigerians are becoming increasingly weary of the what many see as the inability of security forces to deal with this growing threat. Boko Haram claimed responsibility for a bombing of the U.N. Nigeria headquarters in Abuja that killed 26 people in August -- its second strike on the capital.

The Hilton and Sheraton hotels in Abuja were quiet on Monday. Soldiers stood idly where large queues of cars usually form at security gates. The undersides of vehicles were checked as usual for explosives using pole-mounted mirrors.

Shola Adeyemo, head of public relations at the Hilton, said the Muslim public holiday was the main reason the hotel was quiet, but that the U.S. embassy warning may have had an impact.

We do not know the source of the U.S. information but anyway we have been on high security alert since the U.N. bombing, he said. Nigerian authorities ... have given no indication of a new threat.

He added that he was surprised the U.S. embassy did not consult the hotels before making the statement.