Four people were injured after a cooking gas cylinder burst in Paschim Vihar early on Saturday. The police said the incident was reported around 2.30 am and that Patti Ram (20),Charan Singh (40),Rakesh Kumar (25) and Gopal (20) received serious burn injuries. The condition of Patti Ram and Rakesh Kumar is stated to be critical. The police said there was a mini cylinder in their room,which was leaking. When Gopal reportedly struck a match to light his beedi,the leaking gas caught fire,resulting in a blast. The police said all the victims are casual labourers from Uttar Pradesh.