An early morning fire in the press room of The San Diego Union and The Tribune caused an estimated $2.5 million damage and delayed Saturday's edition of the morning Union.

About 200 people were evacuated from the headquarters of the San Diego Union-Tribune Publishing Co., owned by the Copley Press Inc., when the fire began and filled parts of the building with smoke. Employees were allowed to return after about one hour.No one was injured.

The building's fire sprinkler system doused the blaze, which began in a newspaper folding machine, but not before it spread to other areas of the press room, San Diego Fire Department spokesman Larry Cook said.

A malfunction in the folding machine was blamed for the fire, Cook said.