Chief Minister Punjab Sardar Usman Buzdar has paid rich tributes to the great sacrifice of six Pakistan Army martyred officers and sepoys who were performing their duties in a UN Congo Mission and embraced martyrdom in a helicopter accident.CM expressed his heartfelt sympathy and sorrow with the heirs of the martyrs and stated that he is deeply grieved over the martyrdom of officers and sepoys in a helicopter accident.He said that the officers and sepoys of Pakistan Army Aviation Unit by laying down their precious lives have set a high example of their being dutiful.CM tributed that the whole nation is proud of their officers and sepoys for embracing martyrdom while performing their duties in Congo UN Mission.