U.S. Upgrades Terror Warning

July 19 -- U.S. facilities in the Persian Gulf region are on a heightened state of alert, bracing for a possible terrorist assault as early as today.

The State Department said Wednesday it has "strong indications" of an "imminent" terrorist attack against Americans is the Arabian Peninsula, and urged U.S. citizens in the region to "remain vigilant with regard to their personal security and to exercise caution."

"The United States Government has strong indications that individuals may be planning imminent terrorist actions against U.S. interests in the Arabian Peninsula," the department said in a statement.

"As always, we take this information seriously," the statement said.

It said the government had no further information on specific targets, timing, or method of attack, but warned that civilians may be as likely targets as government personnel.

Sources told ABCNEWS that the information the government has received suggests two possible sites for an attack — Saudi Arabia and Kuwait — and indicates a terror assault could occur today.

The sources said the quality of the information is good. It is derived from a coded message believed to have been sent to a very important operative in Osama bin Laden's organization, a person suspected of heavy involvement in coordinating terrorist attacks in the past, the sources said.

U.S. Concerns Persist

The announcement updates a worldwide caution issued by the department in May. At that time, U.S. authorities said they had received information that American citizens abroad might be targeted by extremist groups with links to bin Laden's organization, Al-Qaeda.

Bin Laden, an exiled Saudi millionaire, is accused of orchestrating a wide range of attacks against American interests, including the 1998 bombings of two U.S. embassies in Africa.

Last month, citing information suggesting an "imminent" terrorism attack, U.S. military forces in the Persian Gulf region went on high alert and some 20 U.S. warships were put to sea. Routine military air traffic was halted, the movement of some 20,000 military personnel was restricted, and a Marine Corps exercise was stopped.