Two passengers were killed and at least 23 others injured after a sleeper bus overturned near Delhi’s Karol Bagh area in the early hours of Wednesday, an official of the Delhi Fire Services said.A call regarding the accident was received at 1.10 am, following which two fire service vehicles were rushed to the spot and rescue operations were initiated promptly, the official said.The bus had arrived in Delhi from Jaipur, the official said.The injured were shifted to different hospitals for treatment, the official said.Further details are awaited.