OCEANSIDE, Calif. — Flames caused by an open cooking fire broke out Monday in the Oceanside area, authorities said.

The blaze occurred around 4 p.m. on the banks of the San Luis Rey River, located just east of Interstate 5, the Oceanside Fire Department stated in a news release.

When firefighters arrived on scene, they could see smoke from a distance and identified access points into the river bottom in an area known to have multiple transient camps, according to first responders.

Crews were able to quickly extinguish the fire, containing it to less than one-fourth acre within 25 minutes of arrival.

An occupant of the camp attempting to put the fire out with a blanket suffered minor first degree burns over 1-2% of his body, officials said. The male victim told first responders the fire started from an open cooking fire before being taken to a hospital for further evaluation.

Firefighters were exposed to smoke and poison oak, but no injuries nor damage to structures were reported.

An investigation is underway on the blaze.

The Oceanside Fire Department advises the public to use caution when cooking outdoors and to utilize approved cooking devices away from vegetation.