NEWPORT, Ind. -- Workers dismantling a plant where the deadly VX nerve agent was manufactured in the 1960s stumbled onto a tank last week filled with 20 gallons of the chemical, Army officials said.

None of the workers who found the tank Jan. 19 was exposed, and no VX was released, said Lt. Col. Scott Kimmell, commander of the Newport Chemical Depot.

Depot spokeswoman Terry Arthur said the workers sealed off the area before work began and knew they might discover residual VX. They left when alarms signaled VX might be present, Arthur said.

Workers wearing special gear returned later to take samples to confirm the liquid was VX, she said.

The VX, which has the consistency of mineral oil, was transferred into an approved container and moved to concrete bunkers at the depot, where 1,269 tons of VX are stored.