A security guard who fatally shot a robbery suspect outside an Eagan warehouse being used to process Christmas boxes for underprivileged children early Monday acted in self-defense, according to the early stages of the investigation, police said.

Authorities were continuing to interview the security guard who was being cooperative with investigators working to piece together what happened, said police spokesman Aaron Machtemes.

A security guard called police to report that he had shot a man just after midnight in the parking lot of the building at 985 Aldrin Drive. When officers arrived, they found a man dead of an apparent gunshot wound, Machtemes said.

Initial reports indicate that a masked man approached the security guard and assaulted and attempted to rob him. The security guard then shot the man, who died at the scene, police said. Police said the masked man had a gun.

"At this point it appears the security officer was acting in self-defense," Machtemes said.

Neither the name of the security guard nor the victim has been released.

The security guard was injured during the confrontation, but did not require medical attention, Machtemes said.

Police said the public is not in danger and that they are not seeking additional suspects.

The sprawling 457,000-square-foot building owned by the Meritex Co. was being used by Samaritan's Purse International Relief as a processing center for its Operation Christmas Child program. The center is one of eight across the country where shoe boxes packed with gifts for millions of needy children are collected. Volunteers inspect each shoe box and make it ready to be shipped overseas.

A spokeswoman for Operation Christmas Child said the security guard was not an employee of Operation Christmas Child but was hired by the program. She declined to name the firm the security guard worked for.