Punjab Chief Minister Muhammad Shahbaz Sharif has expressed deep sense of sorrow and grief over the death of a Sikh leader and Chairman Pakistan Sikh Gurdawara Parbandak Committee Sardar Sham Singh at the age of 79 years here on Sunday. In a condolence message, the Chief Minister sympathised with the bereaved family of Sardar Sham Singh and said that he was a patriotic Pakistani.