NORTH BALTIMORE, Ohio — Two freight trains derailed yesterday in the middle of a small northwest Ohio town, with some wreckage falling onto at least one car, authorities said.

Wood County Sheriff Mark Wasylyshyn initially said at the scene there were an undetermined number of injuries.

One injured person was taken to a hospital in nearby Findlay, but a hospital spokeswoman did not have information about the person’s condition.

Authorities and the trains’ owner, CSX Corp., said one train derailed, sending wreckage into another nearby train and knocking some of its cars off a different track.

They did not know what caused the first train to derail.

“One in particular vehicle that I was looking at, it appears that something came off the railroad car and struck the vehicle,” Mr. Wasylyshyn said.

People working for CSX on the scene reported that the train carrying mixed freight was traveling west when it derailed about 12:30 a.m., spokesman Gary Sease said from the company’s headquarters in Jacksonville, Fla. The other train, which was carrying coal, was facing east on a different track, but Mr. Sease was unsure whether that train was moving.

Freight traffic was shut down on the track that CSX says is a busy one for the company. CSX was unsure how long the train service would be disrupted.

A high school, some houses, and a grain elevator were nearby. Classes continued at the school.

CSX operates 2,100 miles of track in Ohio and handles 280,000 carloads of freight annually. Products shipped through Ohio include coal, automobiles, and steel.