A vegetation fire was burning in Benicia near Lake Herman Friday afternoon, prompting a large response from fire units in the air and on the ground, authorities said.

Cal Fire said on social media that the Herman Fire had burned about 167 acres on the northern edge of Benicia along Lake Herman Road as of 4 p.m., with 30% containment.

Firefighters were working on strengthening containment lines and putting out hotspots, Cal Fire said. The agency said it was working the fire in unified command with the Benicia Fire Department.

Earlier, Cal Fire said crews had made good progress in slowing the progression of the fire, which had shown a moderate rate of spread after it was originally reported at around 2 p.m.

No injuries were reported, and no structures appeared to be immediately threatened.

There was no word on the cause of the fire.

This is a breaking news update. More information to be added as available.