The day after a suicide bomber wearing an Afghan National Security uniform blew himself up, killing the police chief of Kandahar, another bomber also wearing a police uniform has killed five NATO service members and four Afghan National Army soldiers. The blast occurred at an early Saturday morning meeting of the Afghan 201 Corps in eastern Afghanistan, and NATO officials are calling it one of the worst of its kind. The Taliban claimed responsibility for the attack, saying it marked the beginning of the spring campaign. “We had recruited this man one month ago and he was serving as an Afghan soldier for the last month,” said Zabiullah Mujahid, a Taliban spokesman. U.S. officials say they are concerned that the Afghan army and police are being infiltrated as their ranks increase rapidly.