Bahrain said today that it had arrested five Bahrainis for allegedly planning terrorist attacks in the country, where the headquarters of the U.S. Navy's 5th Fleet is located, the official Bahrain News Agency reported.

The plot targeted Americans in Bahrain, and two of the five men arrested were members of the island state's military, according to a senior official quoted by the news agency.

"Security forces arrested a cell which was planning terrorist attacks after receiving information on their movement which targeted national interests in the kingdom and the lives of innocent nationals," the news agency quoted a security official as saying.

The agency reported no specific information on what might have been the target of any attack or when the arrests were made. Bahraini officials declined to provide further details.

Ammunition and weapons were seized during the arrests, the news agency reported.

"Investigations have started with this terrorist group to find out if they belong to certain political organizations or if they were working alone," the security official said, adding that the suspects would be handed over to the courts for trial.

The arrests came as anti-American sentiments in the Persian Gulf region increased ahead of a possible U.S.-led attack on Iraq.

Bahrain, where about 4,000 U.S. troops are stationed aboard 5th Fleet ships, is likely to be a launchpad for any attack.

The U.S. Navy headquarters in Bahrain said security was boosted earlier this week after warnings from local authorities.

"We had a higher state of security from Thursday to Friday before they confirmed that these guys were arrested. It went back down today," Navy spokesman Capt. Roxie Meritt said.

The U.S. Embassy in Manama, the capital, issued an advisory on Wednesday notifying citizens that the State Department had authorized the voluntary departure of embassy family members and non-emergency personnel.

"Private U.S. citizens should evaluate rigorously their own security situation and should consider departing," the advisory said.