KITTERY — A tractor-trailer jackknifed on the Maine Turnpike in Kittery this morning, backing up traffic for several hours.

The tractor-trailer jackknifed around 6 a.m. and blocked two of three southbound lanes near mile marker 1, according to a news release from Steve McCausland, spokesman for the Maine Department of Public Safety.

The driver of the truck, 55-year-old Paul Regan of New Hampshire, sustained minor injuries and was taken to a hospital in Portsmouth, N.H.

State police said the crash took place after Regan swerved suddenly to avoid hitting a second big rig. Regan said he swerved his rig across three lanes of traffic to avoid the collision.

The truck slammed into the concrete barrier in the median and jackknifed. The empty truck, owned by New England Motor Freight of Elizabeth, N.J., was traveling from Scarborough to North Reading, Mass. The tractor portion of the vehicle was demolished.