Brush Fire With 'Dangerous' Rate Of Spread Burning On Otay Mountain In San Diego County

SAN DIEGO, CA — A wildfire scorched dozens of acres Thursday afternoon on Otay Mountain in San Diego County.

The blaze, called the Border 2 Fire, sparked west of Doghouse Junction in the area of Otay Mountain Truck Trail, according to Cal Fire. The fire was burning with a "dangerous" rate of spread.

• See latest: Border 2 Fire Forces Evacuations In Otay Mountain Area

As of 2:42 p.m., the fire had scorched 20 acres and was 0% contained, according to Cal Fire. By 8:46 p.m., the fire had scorched 600 acres and remained 0% contained.

"There is a potential of 200 acres and additional resources have been ordered," Cal Fire said on social media shortly after the blaze broke out.

A total of 91 personnel were assigned to the fire, including six engines, four helicopters, four water tenders, four crews and two dozers.

Heavy smoke was visible in the area.

"Although smoke is visible, at this time there is no threat to the city of Chula Vista," the Chula Vista Fire Department said on social media.

The cause of the fire was under investigation.

The fire broke out amid critical fire weather conditions in the region. A red flag warning was extended until 10 a.m. Friday for the county's inland valleys and mountains, according to the National Weather Service. A high wind warning was also in effect until 6 p.m. Thursday for the mountains and valleys.