Bath Iron Works says three of its employees assigned to the Washington Navy Yard where a shooting took place are accounted for and safe.

At least six people were killed in the shooting on Monday.

The three employees are permanently assigned to the home of the Naval Sea Systems Command. But spokesman Jim DeMartini says the workers’ offices are actually outside the Navy Yard. DeMartini says the Bath shipyard’s security staff was advised to be “extra attentive” in light of the shootings.

The Naval Sea Systems Command oversees contracts for Navy warships built at Bath, as well as submarine overhauls at Portsmouth Naval Shipyard.

A spokeswoman for Portsmouth Naval Shipyard in Kittery, Maine, said none of its personnel were affected. She declined to discuss security.