A small plane has crashed into a San Diego neighbourhood in fog, setting about 15 homes on fire as well as vehicles, and forcing evacuations along several blocks.

“We have jet fuel all over the place,” Assistant Fire Department Chief Dan Eddy said on Thursday (local time).

“Our main goal is to search all these homes and get everybody out right now.”

Photo: AAP

He said “there is a direct hit to multiple homes” in the Murphy Canyon neighbourhood and described “a gigantic debris field” in a dense, packed neighbourhood that is home to military families.

At least two people have died and eight are injured, while 10 buildings are damaged, San Diego Police Department confirmed.

People in the neighbourhood described being awakened by a large boom and seeing an orange glow in the sky.

Eddy said it was very foggy at the time the private plane crashed.

“You could barely see in front of you,” he said.

The Cessna 550 aircraft crashed about 3.45am local time near the Montgomery-Gibbs Executive Airport, the Federal Aviation Administration said.

“The number of people on board is unknown at this time,” the FAA said in a statement.

The plane can carry six to eight people.

-with AAP