Somis, Calif. ? An Amtrak train collided with a dump truck crossing the tracks in southern California, injuring 20 people, two of them seriously, officials said.

It was the second collision between an Amtrak train and a dump truck in the country this week. On Tuesday, a train hit a truck crossing the tracks in North Carolina, killing two people.

The two occupants in the dump truck in the California crash Friday were taken to the hospital with serious injuries, said Joe Luna, a Ventura County Fire Department spokesman. Their conditions were not immediately available.

Eighteen of the Surfliner train’s 168 passengers and crew suffered minor injuries, said Amtrak spokeswoman Vernae Graham. All were released from hospitals by Saturday morning.

The cause of the crash in this rural farming town about 50 miles northwest of downtown Los Angeles was not immediately known, Graham said.