The Star Tribune's printing plant was vandalized in the early morning hours Tuesday after a burning projectile was thrown at the building's entrance and graffiti was spray painted on the side of the building.

The damage occurred at the Heritage Printing Facility in the North Loop about 1:45 a.m. when vandals smashed a window at the visitor entrance and threw at the building a "makeshift explosive" that appeared to be a bottle with something flammable in it, according to Steve Yaeger, Star Tribune chief marketing officer and senior vice president of circulation.

The bottle fell to the ground and ignited a small bush, which staff quickly contained, he said.

Security video captured at least two vandals splashing paint on the side of the building and writing obscenities "derogatory to the Star Tribune," Yaeger said.

Police and fire officials were called to the scene. No one was hurt, although production was temporarily halted to ensure employees were safe.

Although the printing facility is staffed overnight, "people who are working at that hour are typically pretty far away from the front of the building," Yaeger said.