On the day of Ashura, the Shiite Muslims mourn the death of Hussein, the grandson of the Prophet Muhammad, who fell in the battle of Karbala against Yazid bin Ma'awiya the Umayyad.
As part of the reenactment of the tragedy that prevented Hasin from inheriting his grandfather according to the Shiite faith, their mourning rituals include wearing black, beating the body and sometimes also "Tatbir", using knives and swords to self-injure the head until it bleeds, including babies.
The video attached shows the beginning of the ceremony in Manchester, England. It should be noted that this is only the beginning of the ceremony in which they start to "encourage" each other, each one doing what he can to outdo the others in his mourning.
Then they begin the violent stage, the knives come out and the blood flows, usually from wounds in the head which brings the largest amount of blood.
The second video's location is unknown.
Source: Moran T - Telegram