KILLEEN (July 29, 2009)--One Killeen firefighter was injured Wednesday while battling a blaze that started in the bedroom of a four-plex where officials say two young children were playing with a cigarette lighter.

The fire was reported just after 10 a.m. Wednesday at the complex at 1703 Cedar Hill Dr.

Residents of an adjoining unit were evacuated.

The other two units were vacant, fire officials said.

One firefighter suffered minor burns and was treated at the scene.

The crews also had to contend with temperatures around 90 degrees.

Additional units were dispatched in order to give the firefighters a break and time to rehabilitate.

Killeen Fire Chief Jerry Garza said the fire appears to have started in a bedroom where two boys, ages 5 and 6, were playing with a cigarette lighter while their mother slept and another resident showered.

Billowing smoke awakened the mother, who rounded up the children.

They escaped safely.

Firefighters were mopping up the fire just before noon.

Officials are assessing the fire damage to the building, but said all four units were heavily damaged by smoke.