A freight train derailed Saturday in northern Nevada, triggering a bridge collapse and disruptions in rail service on one of the country's main east-west lines, Union Pacific officials said.

The derailment occurred in a remote area along the Humboldt River about 10 miles west of Carlin and 260 miles east of Reno, rail company spokeswoman Zoe Richmond said.

Thirteen cars containing grain were involved in the derailment. Richmond she was unsure how many cars the westbound locomotives were hauling. No injuries were reported.

The 102-year-old bridge spanning the river collapsed a couple of hours after the derailment, Richmond said, and railroad officials are unsure how long it'll take to restore it.

"We have crews looking at how to clear the mess," Richmond said. "Any derailment is tough, but we knew this one would be a bit tougher because it involved both a bridge and a derailment."

The line across northern Nevada connects Oakland, Calif., and Salt Lake City as well as other points east.

With the line shut down, Union Pacific's closest alternate east-west lines are located well to the north and south, with one going through Portland, Ore., and the other passing through Las Vegas.

Amtrak uses the same line, but it was not immediately clear the impact the bridge collapse would have on its California Zephyr service, a spokeswoman said.

Union Pacific officials said they hope to come up with a plan by Monday on how to deal with the bridge.

"We once fixed another bridge in about a week, and we should know in the next couple of days how long it's going to take to get this bridge up and running," Richmond said.

The train was passing through an 875-foot tunnel when the derailment occurred. Three cars derailed inside the tunnel and at least a couple of cars ended up in the river, Richmond said.

The cause of the derailment is under investigation by the rail company.