Firefighters responded Friday to four separate vegetation fires at Vandenberg Air Force Base.

Vandenberg crews — assisted by units from Santa Barbara County — responded shortly before 12:30 p.m., and were able to extinguish all the blazes within 90 minutes, said Larry Hill, chief of community relations for the 30th Space Wing at the base.

A total of 7.5 acres were charred, Hill said.

No structures were threatened, Hill said, and the cause of the fires remained under investigation.

Personnel on base were asked to avoid the area northwest of El Rancho Road and Umbra Road, Hill said.

— Noozhawk executive editor Tom Bolton can be reached at tbolton@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.