Five or six militants wearing security uniforms entered the school, officials said. Gunfire and explosions were heard as security forces surrounded the area.<br /><br />The army says most of the school's 500 students have been evacuated. It is not clear how many are being held hostage.<br /><br />A Taliban spokesman says the assault is in response to army operations.<br /><br />Hundreds of Taliban fighters are thought to have died in a recent military offensive in North Waziristan and the nearby Khyber area.<br /><br />A school worker and a student interviewed by the local Geo TV station said the attackers had entered the Army Public School's auditorium, where a military team was conducting first-aid training for students.<br /><br />Many of the casualties were reportedly caused by a suicide blast.
