SAN BERNARDINO ( — A four-alarm fire that erupted at a San Bernardino pallet yard is suspected to be arson, authorities said early Friday.

The fire was first reported at 3:58 a.m. in the 1200 block of South Mountain View, San Bernardino County fire spokesman Jeff Allen said. The flames were declared knocked down at about 6 a.m.

At its peak, an acre of wooden pallets were ablaze.

The blaze drew response from more than 100 firefighters from multiple agencies.

Friday’s fire was the latest in a series of recent industrial center fires reported in the Inland Empire, leading to suspicions of arson.

The flames had spread to eight businesses next door in a strip mall, but minimal damage was reported.