LAHORE(National times)- A man and his son were killed and three other persons sustained injuries in a gas cylinder explosion in Kahna area of Lahore on Thursday night, Dunya News reported. According to details, the cylinder exploded a house located in the Nishtar Colony. Fire broke out after the explosion due to which smoke accumulated in the house as a result, a man and his son died of suffocation while three other persons were wounded. Police and rescue teams reached the spot after getting information and shifted the dead and injured to hospital.