OAKLAND (CBS SF) — Arson investigators were at a two-alarm vegetation fire that burned near Interstate 880 and the Oakland Arena early Tuesday morning, the fire department said.

The fire was reported just after 4 a.m. next to East Bay Municipal Utilities District property near Oakport St. which is a frontage road on the west side of I-880.

A second alarm was called at 4:23 a.m. and the grass fire was contained by 4:39 a.m. after burning about three-and-a-half acres burned. Oakport St. was closed between 66th Ave. and Hyde St as firefighters continued to mop up.

There is a homeless encampment in the area, but fire officials said the encampment was not involved and investigators were looking into arson as the possible cause.

No one was injured and there was no one displaced by the fire.