Awwal 07, 1432, Feb 10, 2011, SPA -- A teenage suicide bomber Thursday killed at least 27 soldiers and injured 40 more at a parade ground at an army training centre in north-western Pakistan, officials said. According to dpa, the attack took place in Mardan city in Khyber-Pakhtunkhwa province when soldiers of the Punjab regimental centre were doing morning exercises. All those killed and injured were army men, said Muhammad Adil, the top civilian administrator in Mardan. Abdul Samad Khan, a senior police official, said the bomber managed to sneak into the otherwise heavily guarded training centre wearing a school uniform as a disguise. No group had claimed responsibility for the attack, but the Taliban have targeted Pakistani soldiers in the past in retaliation for security actions against their bases in the tribal region along the Afghan border. A Pakistani military spokesman, Major General Athar Abbas, said this week that 2,700 troops and 300 intelligence agents have been killed in such attacks since 2003.