Three persons were killed and 16 others wounded after a sticky bomb struck a police vehicle in Afghan capital on Thursday, an official said.The blast took place at 06.30 p.m. local time in Chendawal area and two police officers and one civilian were killed and 14 civilians and two policemen were injured, Interior Ministry spokesman Najib Danish said on Facebook, Xinhua news agency reported.The blast occurred when the police vehicle was patrolling a busy road. The vehicle was also destroyed in the explosion.No group has so far claimed responsibility for it.