AUSTIN, Texas (Reuters) - Texas executed a man on Thursday evening convicted of killing former co-workers at a Texas car wash 12 years ago, the Texas Department of Criminal Justice said.

The lethal injection of Robert Wayne Harris, 40, was the second execution in the United States on Thursday. Earlier in the day, Donald Palmer, 47, was executed in Ohio for a 1989 double murder.

Prosecutors said Harris shot six employees, five fatally at close range, after forcing them to the floor during a robbery at the Mi-T-Fine Car Wash in Irving, Texas, on March 20, 2000. Harris was convicted in two of the deaths.

(Reporting By Corrie MacLaggan, Terry Baynes and Jonathan Stempel; Editing by Cynthia Johnston)