A contract security guard at Lockheed Martin's Archbald facility fatally shot an employee Tuesday morning and then killed himself, the company said.

"The incident took place at approximately 9:30 a.m. Eastern time and is believed to involve a personal matter," the defense contractor said on the Web site for its Missiles and Fire Control unit in Archbald, outside Scranton. Names of the victims are being withheld pending notification of next of kin, the company said, while Lockheed officials continue to work with local law enforcement at the scene.

"The safety of our employees is our highest priority and all have been evacuated and will not be returning to work today. We are shocked and saddened by this tragedy and express our deepest sympathies to the families," the company wrote.

The site has 580 employees and its products include laser-guided bombs and training rounds for the US Air Force and specialized instrumentation, control devices and shipboard packaging for the Navy. 

For more information, visit: www.lockheedmartin.com/mfc or www.wnep.com