The actor, who was not injured, later expressed his shock at bystanders' apathy towards those injured in the incident.
The bus also hit an auto-rickshaw, and a woman and a girl travelling in the rickshaw suffered minor injuries, Cyberabad police here said.
The incident occurred last night when Raj was heading for Shilaparamam after completing a shoot at Madhpur.
As his car stopped at the red light, the bus crashed into it from behind.
"Had a miraculous escape as a bus rammed into us from behind at a tragic signal. Cars jammed. Family thrown out of an auto. Chaos but...It was terrifying to see the youngsters... Instead of saving People who were lying thrown around... They were busy taking pictures.. Shame," the actor tweeted afterwards.
"Realised my helplessness n the fragility of this life.. The only way is to live it as long as it lasts," the actor tweeted further.
The bus driver Mallareddy was today arrested, inspector K Narsimulu of Madhpur police station told PTI.