RIYADH, Saudi Arabia (AP) — The U.S. Embassy in Saudi Arabia has warned American citizens that extremists may be planning to attack Westerners in the country.

The warning issued Wednesday said the timing and method of the potential attacks were not known.

"... We have received credible information that an unidentified extremist(s) in Saudi Arabia may be planning to attack Westerners working and living in Al-Qasim, Saudi Arabia," the U.S. warning said. Al-Qasim is an ultraconservative province northwest of the capital Riyadh.

The Embassy urged U.S. citizens to "exercise prudence and enhanced security awareness at all times."