RIYADH, Saudi Arabia, AP -The U.S. Embassy warned Americans in Saudi Arabia on Monday that militants are likely plotting new terror attacks in the kingdom.

The embassy”s message, posted on its Web site, said there were &#34continued indications of operational planning for a terrorist attack or attacks&#34 in Saudi Arabia. It offered no specific information.

&#34U.S. military personnel stationed in Saudi Arabia have been instructed to suspend all non-duty related leisure travel outside of their work or housing stations,&#34 the message said. It urged Americans to be vigilant and avoid areas frequented by Westerners.

It was the second such warning posted in the past week by the embassy in Riyadh.

Also Monday, Saudi security forces detained a wanted Saudi-born al-Qaeda operative, Mohammed Saeed Mohammed al-Sayam al-Umari, 25, in Medina, one of Islam”s holiest cities.

No further details were provided.

Al-Umari”s name was No. 10 on a list of 36 most wanted terrorists sought for connection to terror attacks in the kingdom dating back to 2003.

Since May 2003, Islamic militants have carried out numerous suicide bombings and kidnappings and have regularly battled security forces. The attacks, which have tended to target Westerners and housing complexes were Westerners live, have been blamed on the al-Qaeda terror group and its allies.