Firefighters in the upper Valley have been busy trying to put out grass fires this past week.

A Red flag warning on Thursday and breezy conditions in all four Valley counties have increased fire weather conditions, meaning any fires that break out will spread quickly and will be hard to contain, according to Meteorologist Cecilia Gutierrez.

RELATED: Fire chief: Brush fire in Alton fully contained

Alton fire Chief John Salinas said four acres burned Tuesday and nearby houses were evacuated. The blaze was able to be controlled, but the next day, a small fire was still lingering among a pile of tires, wood and building materials.

“All of our resources are being tied-up right now,” Salinas said. “We are getting assistance.”

A few miles north in La Homa, another grass fire burned the roof of a home.

Officials say if someone is caught intentionally starting a fire, they could face a fine of up to $500.