PINE BLUFF, Ark. - Laboratory tests show that a trace amount of a chemical agent has leaked from a rocket in storage at the Pine Bluff Arsenal, but officials said Thursday that it was contained and poses no threat to the public or arsenal workers.

The chemical was detected during routine testing on Thursday, arsenal spokeswoman Carole Newton said. The sarin rocket was in a filtered M-55 storage unit, and none of the chemical was released into the atmosphere, she said.

An arsenal crew entered the storage unit and was going from rocket-to-rocket in an effort to isolate the leak. Newton said the specific rocket had not yet been found.

Local officials were notified immediately after the leak was detected, she said.