Shots were fired outside a U.S. military training post near Hattiesburg, Mississippi, while soldiers were taking part in exercises, authorities said on Tuesday, and a search was under way for two male suspects driving a red pickup truck.

No one was injured, said Lieutenant Colonel Christian Patterson, director of public affairs at the Mississippi Military Department, and it was unclear if military personnel were targeted.

The Perry County Sheriff's Department questioned two men after authorities found a truck matching the description of the vehicle driven by the suspected shooters, according to the Mississippi Highway Patrol.

But later the two men were released without charges, WDAM TV reported on its Twitter account, and police resumed their search for the pickup.

Soldiers at the camp, located 110 miles (177 km) north of New Orleans, reported the shots to their commanding officers, who in turn told local authorities, Patterson said in a news release.