A wildfire that erupted Thursday west of Temecula charred about 15 acres as it moved toward San Diego County.
The non-injury blaze was reported at 11:20 a.m. in the area of Via Volcano and Los Gatos Road, in the unincorporated community of De Luz, where houses are spread out on large lots along hillsides.
By noon, the brusher was burning on the boundary separating Riverside and San Diego counties. No homes or other structures were immediately threatened.
Five Cal Fire air tankers and two water-dropping helicopters were the first to reach the area and began making runs on the brusher about 11:45 a.m.
Multiple engine crews and hand crews from Riverside County, San Diego County and the Cleveland National Forest were sent but had difficulty reaching the blaze, shortly before 1 p.m. they were still attempting to gain access, staging at De Luz and Tenaja roads.
Under a mutual aid agreement signed earlier this summer, Riverside County and San Diego County fire crews are generally expected to deploy together whenever a blaze is within five miles of the county line.
There was no word on what sparked the brusher.