CUDAHY, Wis. (AP) -- The mayor of Cudahy, Wis., has declared a a state of emergency as fire continues to burn at a meatpacking plant.

The fire at the Patrick Cudahy plant south of Milwaukee has prompted residents and businesses within a mile radius to evacuate. There are concerns about exposure to toxic fumes and the possibility that containers filled with ammonia could explode.

Mayor Ryan McCue says he made the emergency declaration so that city officials could request more resources from Milwaukee County and the state.

About 100 firefighters have been fighting the blaze. No injuries are reported.

The plant is owned by Smithfield Foods Inc., the nation's largest hog producer and pork processor.

(Copyright 2009 by The Associated Press. All Rights Reserved.)