The fall of Mazyar and al-Afshin

In 225 AH Mazyar ibn Qarin, lord of Tabaristan, was brought as a captive to Samarra, and al-Afshin died in prison, as al-Mas'udi relates. ¹

Al-Mas'udi says that al-Hasan ibn al-Husayn ibn Mus'ab skirmished with him and then he was carried off as a captive. Mazyar admitted that al-Afshin had sent him to rebel, on behalf of one of the Manichaean or Magian doctrines. He was beaten with a whip until he died, and crucified beside Babak. ¹

Al-Afshin died in prison, and was crucified at the gate of the common people. Idols were thrown on him, said to be the ones that had been carried to him, and fire was set to them, and it consumed everything. ¹

This is al-Mas'udi's account. An additional source is needed.