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.

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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.

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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.

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