A day of national mourning is being observed today in Pakistan to express fraternal solidarity on behalf of Government and the people of Pakistan with the Government and the people of Iran, on the sad demise of Iranian President Sayyed Ebrahim Raisi and other Iranian dignitaries in the helicopter crash incident.The National flag will fly at half-mast throughout the country today.The day of national mourning has been declared by Prime Minister Muhammad Shehbaz Sharif.Source: Radio Pakistan