JOHANNESBURG—South Africa's police watchdog said Friday it arrested eight policemen on charges of murder in connection with the dragging death Tuesday of a 27-year-old Mozambican man in police custody that was captured on video.

The announcement comes after public uproar over the death of the man, identified by police as taxi driver Mido Macia. His death came to light on Thursday after a video taken by a bystander—and aired on local television—showed Mr. Macia being strapped to a police van and then dragged down the street. He died in custody several hours later in Daveyton, on the outskirts of Johannesburg.

The eight policemen, who had earlier Friday been suspended from active duty and disarmed by the country's police commissioner, will appear in the Daveyton Magistrate's Court on Monday, said Moses Dlamini, a spokesman for the Independent Police Investigative Directorate, a government arm that investigates potential criminal offenses by police.

The arrest comes after South Africa's ruling party, president and acting police minister called for action.

"All police officers have a duty to fight crime and those who are not worthy of wearing our badge and uniform must know that they have no place within [the South African Police Service]," said acting Minister of Police Siyabonga Cwele.