Seven people were killed in two related shootings at a mushroom farm and a trucking firm in a coastal community south of San Francisco on Monday, officials said.

San Mateo County Board of Supervisors President Dave Pine says four people were killed at the farm and three at the trucking business on the outskirts of Half Moon Bay, a city about 30 miles south of San Francisco.

It was not immediately clear how the locations were connected.

The San Mateo County Sheriff said on Twitter: "The Sheriff's Office is responding to a shooting incident with multiple victims in the area of (Highway) 92 and the (Half Moon Bay) City limits.... Read More: Arutz-7