OKLAHOMA CITY - Firefighters are expecting a long night ahead of them as they watch for "hot spots" after several grass fires ignited in southeast Oklahoma City.

By 6 p.m. Sunday, the largest fire, just north of SE 164 Street at Air Depot was still burning. Crews focused much of their efforts there because there are several homes in this area. 

Smoke billowed into the air as firefighters battled a wildfire below.

"By the time we got on scene it was about 100 acres," said Battalion Chief Greg Lindsay, Oklahoma City Fire Department. 

The area is home to about 60 miles of dirt trails managed by the CrossTimbers Riders Association (CRA). A group of bikers saw the flames and called for help.

"They pulled up on that hill there was already a fire they tried to get it out and it just got out of control because of the wind and decided to get out of there," said Chuck Howard with the CRA. 

The fire grew from 200 acres to more than 800 acres and kept moving south. The thick terrain made the battle that more difficult.

"We've got water supply issues, but we've got the tankers and we're keeping track of our brush pumpers," said Lindsay.

As the fire grew, so did the need for reinforcements. Agencies from at least six nearby fire departments came out to help Oklahoma City get this fire under control. 

"Right now, the biggest challenge is the wind," Lindsay said. 

There are no injuries reported at this time, and so far, the fire has destroyed two outbuildings and damaged two homes.