Air and ground crews from the Contra Costa Fire Protection District battled a Brentwood brush fire that quickly grew from 5 acres to 50 acres Sunday afternoon.

Authorities said the fire broke out near Walnut Boulevard and Camino Diablo, south of Brentwood. The call came in at 3:22 p.m.

The “forward progress” or the fire movement was halted at approximately 50 acres, according to the fire district’s social media page

No injuries or structural damage have been reported so far, and air resources have been released.

This is a developing story. Come back for updates.