A Czech official says an explosion of gun powder has rocked an ammunition plant in the Czech Republic, killing at least one person.

Firefighters spokesman Ladislav Holomcik says the explosion took place just before 1 p.m. Monday in the Sellier & Bellot plant in the town of Vlasim, 60 kilometers (37 miles) southeast of Prague.

Holomcik says an unspecified number of workers are still missing and rescuers so far are still unable to enter the scene of the explosion.