A transport police officer was driving a car with his son riding as passenger when they hit a motorcycle when the car turned into oncoming traffic Tuesday, RIA Novosti reported Wednesday.
The driver of the motorcycle died at the scene and his female passenger died later in the hospital, the news agency said.
Friends of the bikers showed up at the accident site and allegedly attacked the car's driver and his son, killing the driver, a local police spokesperson said.
The son was hospitalized with head and face injuries, police said.
"After the beating, he [the passenger] managed to call the police. His father was killed," the spokesperson said.
Police said the alleged attackers were drunk at the time of the incident.
If found guilty of intent to cause grievous bodily harm, the alleged attackers could face up to 15 years in prison, RIA Novosti reported.