Iran executed a second prisoner on Monday convicted over crimes committed during the nationwide protests challenging the country’s theocracy, publicly hanging him from a construction crane as a gruesome warning to others.

The execution of Majidreza Rahnavard comes less than a month after he apparently stabbed to death two members of a paramilitary force after purportedly becoming angry about security forces’ killing of protesters.

The development underscores the speed at which Iran now carries out death sentences handed down for those detained in the demonstrations that the government hopes to put down. Activists warn that at least a dozen people already have been sentenced to death in closed-door hearings.

At least 488 people have been killed since the demonstrations began in mid-September, according to Human Rights Activists in Iran, a group that’s been monitoring the protests. Another 18,200 people have been detained by authorities. Iran’s Mizan news agency, which falls under the country’s judiciary, published a collage of images of Rahnavard hanging from the crane, his hands and feet bound, a black bag over his head.

Masked security force members stood guard in front of concrete and metal barriers that held back a gathered crowd early Monday morning in the Iranian city of Mashhad. Mizan alleged Rahnavard had stabbed two security force members to death on November 17 in Mashhad and wounded four others. Footage aired on state TV showed a man chasing another around a street corner, then standing over him and stabbing him after he fell against a parked motorbike. Another showed the same man stabbing another immediately after.

The assailant, which state TV alleged was Rahnavard, then fled. The Mizan report identified the dead as “student” Basij, paramilitary volunteers under Iran’s Revolutionary Guard. The Basij have deployed in major cities, attacking and detaining protesters.

Sikh youth shot dead in Canada

A 24-year-old Indian-origin Sikh man has died of gunshot wounds in the Canadian province of Alberta, with police citing homicide as the reason for his death, the second such incident this month.

The victim, identified as Sanraj Singh, was located by the police in Edmonton city when they responded to a gunshot report on December 3 night, an Edmonton police news release said. Singh was found sitting in a vehicle in medical distress.

The police performed CPR, a life-saving technique, until the Emergency Medical Services arrived and declared him dead. According to the police, a suspect vehicle was seen leaving the area, and photos of the same were released by homicide investigators.

Residents were also asked to check their CCTV cameras or dashcam footage for any suspicious activity on the night of December 3.