SANTA FE SPRINGS, Calif. — An RV stopped on the tracks was hit by a commuter train and burst into flames near Los Angeles, causing widespread rail delays at rush hour Friday, officials said.

There were no immediate reports of major injuries following the fiery collision around 5:30 a.m. at an intersection in an industrial area of Santa Fe Springs.

Passengers and crew on Metrolink's OC Line 681 were safely evacuated, agency spokesman Scott Johnson said.

Passenger Ryan Hajek said he felt the train operator slam on the brakes as it approached the intersection.

"The lights inside went dark, so we knew something went wrong, I knew we crushed into something," Hajek told KABC-TV. "As we stopped, I saw all the debris of what looked like a car on the side of the tracks, and I knew then that we had hit something."

Four people on board complained of pain and were treated at the scene, said Whittier police Officer Hugo Figueroa.

Investigators will try to determine why the RV was stopped on the tracks, Johnson said.

"Our engineer went into emergency stop procedures but unfortunately was unable to stop in time," he said. It wasn't immediately known how fast the train was moving.

Fire crews doused the flames, which gutted the RV and charred a rail car on a freight train stopped on a parallel track.

The freight train was also unable to stop in time and ran over some of the crash debris, according to Lena Kent, spokeswoman for BNSF, which maintains tracks in the area.

Police were looking for four people seen running from the tracks just before the impact, but it wasn't immediately known if they were coming from the RV, Figueroa said.

The collision occurred at a crossing equipped with gates and flashing lights, Kent said. It wasn't clear if the RV tried to drive around the gates, she said.

The Metrolink train with five passenger cars was heading north from Orange County when the crash happened about 15 miles (24 kilometers) southeast of downtown Los Angeles.

Buses were ordered to take 120 evacuated passengers to Union Station in Los Angeles. Widespread delays were expected on Metrolink's Orange County and 91/Perris Valley lines, Johnson said.