Another projectile containing mustard gas was placed in a leak-proof container at the Blue Grass Army Depot after traces of the chemical agent were detected in a storage building, the depot said yesterday.

The leak was found after two other leaking shells in the same building were put in similar containers last month, officials at the Army's Blue Grass Chemical Activity said in a statement.

All three will be moved to another building specially designed for storing leaking weapons, the statement said.

Chemical workers also were trying to identify another mustard-gas rocket leaking in a separate building. Officials said that there was no danger to the public and that emergency officials had been notified.