MINDEN (AP) — An explosion at the Camp Minden industrial site in northwest Louisiana was the source of a loud, ground-rattling boom that shook buildings and shattered windows in the nearby city of Minden late Monday, Webster Parish authorities say.

The Webster Sheriff’s Office said Tuesday that the explosion happened in an underground bunker at a Camp Minden business, Explo Systems Inc.

The company declined immediate comment when reached by phone Tuesday morning and did not take part in a news conference with Sheriff Gary Sexton.

Sexton said the underground bunkers at Explo are designed to direct the force upward. However, there were reports of the blast being felt in several nearby communities. Shattered windows were reported in Minden and Dixie Inn.

No injuries were reported. Residents said they heard the boom around 11:30 p.m. and some saw a bright light at the time of the explosion.

A plume rising in the air over the Camp Minden area registered on National Weather Service radar about that time.

Aaron Stevens at the NWS Shreveport office said the radar indicated a plume rising about 7,000 feet, registering on the radar during three scans that covered about 20 minutes. There were no storms in the area at the time, so “we knew it wasn’t weather,” Stevens said.

The radar image was similar to what would be seen during a wild fire or if a large flock of birds were taking off, he said.

Camp Minden is the site of a former Army ammunition plant. Louisiana took the site over from the federal government in 2005. Now, it is a Louisiana National Guard training site and an industrial complex.

The website for Explo Systems describes the business as an explosive recovering and recycling business.

In 2006, a series of explosions at the plant led to the evacuation of hundreds of people from nearby schools, a jail and the town of Doyline.

Copyright 2012 The Associated Press.