A notice posted on the website of the U.S. embassy in Canada warning Americans of the threat of terrorists "targeting U.S. citizens, including children" is part of a worldwide alert and is not specific to Canada, U.S. and Canadian officials said today.

The warning, issued Friday, urges U.S. citizens abroad to take precautions — to keep a low profile, review travel routes and times to make their patterns less predictable, and remain alert in public places.

"The U.S. government remains concerned that terrorists are intent on targeting U.S. citizens, including children," the Canada-wide warning says. "Terrorists may employ a variety of tactics, such as violent assaults and kidnappings.

"In the past they have used knives, guns, and vehicles as ramming devices. They may target schools, hospitals, churches, tourist locations, transportation hubs, and other public venues."