A small fire in a downtown Minneapolis post office branch sent firefighters busting through the front door in search of flames and forced the office's closing until repairs can be made, authorities said Sunday.

The fire at the Loring Station post office, 18 N. 12th St., was reported to the Fire Department about 11 p.m. Saturday, said Assistant Chief Bryan Tyner.

He said the smoke and flames and the water used to douse the fire in a back room did not cause much harm to the facility, and "none of the mail was damaged." At this preliminary stage, Tyner said, there were no signs to indicate the fire was of a suspicious origin.

However, firefighters had to break down the public entry to get inside the building near the westbound entrance from downtown onto Interstate 394, Tyner added.

The U.S. Postal Service said the station will be closed until repairs can be made.

Delivery, phone calls and retail operations will be moved to the Main Post Office at 100 S. 1st St. until the station reopens. Retail hours there are from 7 a.m. to 8 p.m. weekdays and 9 a.m. to 1 p.m. Saturdays.

Customers with P.O. boxes can get their mail at the Butler Quarter Station at 100 N. 6th St., Suite 120B. Customers must present a photo ID; hours are 8:30 a.m. to 5 p.m. weekdays.

Pat Pheifer and Paul Walsh