At least two US troops and three Afghan policemen have been killed in what seemed to be insider attack in eastern Afghanistan, the country’s officials said.

The attacker in the eastern Afghan province of Wardak was wearing an Afghan police uniform. He opened fire inside a police station while US forces were visiting.

Monday’s shooting is the latest in a series of ‘green-on-blue’ attacks, in which assailants are dressed in police or army uniform.The incident comes days after a suicide bomber on a bicycle detonated an explosion outside the Afghan Defense Ministry, killing nine Afghan civilians and wounding 14 others. On the same day a suicide bomber blew himself up in the eastern Afghan city of Khost, leaving eight children and one police officer dead. The attacks coincided with US Defense Secretary Chuck Hagel`s visit to the capital.

The end of February saw a surge of Taliban attacks with dozens civilians killed. On February 24 Afghan police foiled an attack on a Kabul's diplomatic enclave, killing a would-be suicide bomber. On the same day two suicide bomb attacks killed two intelligence agents and a policeman.

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