Four Afghan policemen were killed and seven others wounded when a colleague opened fire on them at a checkpoint in the southern province of Kandahar, dpa cited police as saying Thursday. The gunman, who joined the police force two years ago, "opened fire on his comrades when they were eating dinner," said Zia ul Rahman Durrani, a Kandahar police spokesman. The attacker was shot and killed as he tried to flee, Durrani said. An initial investigation showed that the attacker was affiliated with the Taliban militant group, which later claimed responsibility for the incident in Zherai district.