A wildfire burning on the south side of Vandenberg Air Force Base near Lompoc grew to 4,500 acres Monday despite an aggressive air and ground attack to stop flames from advancing.

Over the weekend, the Canyon fire forced officials to postpone the launch of an Atlas V rocket. The rocket was scheduled to take off Sunday and carry the WorldView-4, a commercial satellite that snaps high-resolution images of Earth, according to United Launch Alliance, the contractor hired to launch the satellite.

Civil engineers worked on Sunday to restore power in a remote canyon on the base, according to the base. The Air Force has further restricted public access to the site as fire crews worked feverishly to cut new fire lines and douse spot fires.

The wildfire broke out Saturday in a remote canyon at the southern end of the military base and quickly spread to nearly two square miles, according to Wayne Seda, the assistant chief of the Vandenberg Fire Department.

"It's burning in some very tough vegetation," Seda told reporters Sunday. "The fire grew rapidly.... It jumped roads at times and came out of the containment lines."

Nearly 800 firefighters from state, federal and local agencies have been dispatched to battle the blaze, which is burning between Arguello and Santa Ynez Ridge roads.

No injuries have been reported. The cause of the fire is under investigation.

The flames have damaged power lines at the base but no structures have been affected and no homes are threatened, Seda said.