U.S. embassies in Gulf warned of threats

Demonstrations against the U.S. and Israel are common in Sana'a, including this one by Yemeni women earlier this month.

WASHINGTON (CNN) -- In addition to a threat against its embassy in Yemen, the United States has received information about possible threats to other U.S. embassies in the Persian Gulf, a State Department official told CNN Monday.

The U.S. Embassy in the Yemen capital Sana'a closed its doors Tuesday after receiving information about a possible terrorist attack against U.S. interests "on or about April 23, 2002."

A message on the embassy's Web site said there were no details about a possible target.

But a State Department official said new information indicated the threat was not only against the embassy in Yemen but also against U.S. embassies in unspecified Gulf states.

The advisory is in addition to the State Department's worldwide caution to all Americans traveling abroad. A separate traveling warning has been in effect for Yemen for some time and was most recently updated March 18.

Last month, a Yemeni man threw an explosive device at the embassy.

In the advisory, the embassy urges Americans to keep a low profile, vary their routes and times of travel, and to avoid large crowds and demonstrations. Sana'a has seen several pro-Palestinian protests in recent weeks.

In addition, the embassy "strongly recommends that American citizens lock all their car doors and keep their windows rolled up when driving" and to register with the embassy.

The United States has said it believes members of Osama bin Laden's al Qaeda organization are hiding in Yemen despite increased measures by the Yemeni government to crack down on terrorist groups in the country.

Shortly after Vice President Dick Cheney's visit to Yemen in March, a senior U.S. official told CNN the Pentagon was considering sending 40 to 80 troops to Yemen to train and equip the country's military in counterterrorism in a mission similar to the one in the Philippines.

A U.S. team is currently in Yemen to install computers, cameras and other sophisticated equipment at airports, harbors and border crossings to help Yemeni officials intercept al Qaeda members and other terrorists.

In October 2000, the USS Cole was the target of a terrorist attack in the port of Aden that killed 17 crew members and injured 39 others. The United States blames al Qaeda for the Cole bombing and the September 11 attacks.

Navy officials have told CNN there are no immediate plans to redeploy ships to Yemen largely because of security concerns.

Although the Navy considers Aden is a useful port, officials said the U.S. military has other options in the region just as suitable. One possibility is to use space across the Gulf of Aden at a French naval base in Djibouti.

-- CNN Producer Elise Labott contributed to this story.