UPDATE (2:41 p.m.): According to CDOT, I-25 has reopened, but the interstate is still experiencing heavy backups. Alternate routes are advised.

CASTLE ROCK, Colo. — The Colorado Department of Transportation is warning drivers of a closure on southbound I-25 at Tomah Road in Castle Rock.

The closure went into place at about noon on Wednesday.

CDOT is citing the reason for Wednesday’s road closure as “fire activity,” between Exit 174 (Tomah Road) and Exit 163 (County Line Road).

Colorado State Patrol told FOX21’s sister station in Denver this is a hazmat situation.

There is no estimated time for the interstate to re-open.

This article will be updated.