NAVASOTA, Texas (AP) More than a half-dozen Union Pacific tanker cars have derailed in Central Texas and some are leaking a chemical used in natural gas processing.

The Grimes County Sheriff's Office says nobody was hurt in Monday's derailment near Navasota (nah-vuh-SOH'-tuh), about 65 miles northwest of Houston.

Chief Deputy Todd Greene says seven or eight cars derailed and some are leaking diethanolamine (dy-eth-uh-NAL'-uh-meen).

Greene says deputies have closed nearby Highway 6. Nobody has been evacuated.

Sheriff Don Sowell told KBTX-TV that there may be damage to the Highway 6 overpass.

Messages left with Union Pacific were not immediately returned.