Two Muslim clerics were stabbed at Iran’s Imam Reza Shrine on Tuesday, the religious site said in a statement reported by official media. Amateur video footage showed a man lying in a pool of blood in the courtyard of the Shia shrine in Mashhad in northeastern Khorasan province. The two men “were stabbed with a knife in the courtyard,” the statement said, adding that the attacker had been arrested. “No details are available about the health situation of the two clerics,” said state-run IRIB TV. “The identity of the assailant is under investigation,” said the Astan Quds Razavi charitable founda…