KARACHI - An unmanned Pakistan naval aircraft crashed in the southern city of Karachi on Tuesday, but there was no damage on ground, police and naval officials said."It was a Pakistan Navy UAV (unmanned aerial vehicle) and it was on a routine training sortie when it was hit by a bird," said Pakistan navy spokesman Commander Salman Ali.The UAV, commonly known as a drone, is used by the navy for surveillance, reconnaissance and photography, he said.He did not give details on the make and manufacturer of the aircraft.