Martyrs of Karbala are those who were martyred on Muharram 10th (‘Ashura') 61AH(680AD) , in Karbala by 'Umar b. Sa'd's army. Martyrs of Karbala include Imam al-Husayn (a), some members of Banu Hashim (Hashemites) and some of his companions. The exact number of martyrs of Karbala is unknown; however according to what is reported by majority of historians they were 72. Some martyrs are mentioned in all of the books, in which the event of Karbala is narrated, but some are only mentioned in some sources. 18 martyrs are from Banu Hashim (Hashimites) and the rest are Imam al-Husayn's companions. 'Abbas b. Ali and 'Ali al-Akbar, Imam al-Husayn's son, are the best known martyrs of Banu Hashim and Hurr b. Yazid al-Riyahi, Habib b. Muzahir and Muslim b. ‘Awsaja are the famous martyrs among Imam's companions. Except for Hurr b. Yazid, all the martyrs were buried in Karbala.