WACO, Texas (KWKT) — A multiple alarm fire was burning at the M&M Mars plant in Waco early Tuesday afternoon,  leading to the evacuation of employees from the plant.

Fire was reported in storage containers on trucks parked at the facility. A large smoke plume was visible over the area of the plant.

Police had closed portions of Texas Central Parkway, Mars Drive, Old Hewitt Drive and Imperial Drive. The first fire alarm came in at 1:08 p.m. with the first unit arriving two minutes later.

While roads were blocked to keep motorists away from potentially harmful fumes, winds were blowing in a direction that did not require evacuation of Midway High School.

The actual fire was confined to the trailers outside the plant buildings. It started in one of the trailers, but gusty winds soon spread it to five others.

Exactly what caused the fire has not been determined. Damage to the buildings from smoke was expected to be minimal.

For updates visit MyCenTx.com.