"On behalf of the Iranian nation, I would like to express sympathy and condolences to your Excellency and the friendly and brotherly nation of Pakistan," President Raisi wrote in his message to Prime Minister Sharif.
The Iranian president further condemned the terrorist and indiscriminate act of terrorism, and said, "We believe that such inhumane and criminal acts will yield no result but a disgrace to its perpetrators and agents behind it."
At least 40 people were killed and over 130 injured when a suicide bomber set off explosives at a political convention in Pakistan's northwestern Khyber Pakhtunkhwa province on Sunday.