NEW DELHI — Four police officers have been arrested over the deaths in custody of a father and son who were detained for keeping their mobile phone shop open during coronavirus lockdown in southern India, police said Thursday.

The police are investigating accusations that the officers badly beat the shopkeepers in Thoothukudi, a port city in Tamil Nadu state, last week. They face murder charges, senior police officer K. Shankar told reporters.

The arrests Wednesday and Thursday came after a court ruled that autopsy reports of the father and son suggested the police officers had been involved in the men's deaths by torture.

The court ordered authorities to provide protection to a female police officer who gave an eyewitness account of torture in the police station.

A complaint by family members said the 62-year-old shopkeeper was picked up by police from his shop on June 19. His 32-year-old son who went looking for his father also was detained, and both were tortured and died.

On completion of investigation into torture accusations, police will take the four suspects to court, which will decide whether they should be formally charged with murder, a capital offense.

Police are strictly enforcing lockdown restrictions in containment zones in Tamil Nadu, the second worst-hit state in India by the pandemic.