Afghan police say four officers were killed and seven others wounded when a colleague opened fire on them in the southern province of Kandahar.
Provincial police spokesman Zia Durrani said the shootings took place at a checkpoint in the Zhari district late on February 10.
He said the rogue policeman, who joined the police force two years ago, was shot dead by another officer.
The Taliban claimed responsibility for the attack, which comes after a rogue police officer drugged and then shot dead 10 colleagues in the central province of Uruzgan on January 26.
Earlier in January, nine policemen were shot dead in the same province by four rogue colleagues.