TOOELE, Utah (AP) - Officials at the Deseret Chemical Depot, which stores and destroys nerve agent, sounded a terrorist alert Thursday morning after a possible intrusion.

Wade Mathews, with the Toole County Emergency Management, said sheriff's deputies setup a roadblock around the depot and the Utah Department of Public Safety was searching the area by helicopter.

A depot spokeswoman was not immediately available for comment or further information.

The depot, about 45 miles southwest of Salt Lake City, has been destroying a stockpile of deadly the chemical weapons since 1996. Earlier this year, it finished destroying the largest stockpile of sarin nerve gas in the United States.