One of Delhi's top 10 gangsters wanted for various serious crimes, including an attack on a former legislator, has been arrested, officials said on Sunday.Vikas Langarpuria, 25, was arrested on Saturday night on a tip-off about his visit to a place here.A notorious extortionist, he had in 2012 attacked former legislator from Najafgarh Bharat Singh, with his men forcing themselves inside Singh's office and shooting him.Langarpuria was arrested from Najafgarh area in 2013 for extorting money from a builder, but released on bail and since then, was on the run. A court here had declared him a proclaimed offender.He and his gang were involved in several cases of murder, robbery and extortion in Delhi and Haryana. The gang had many sharp-shooters, who used sophisticated weapons, police said.Langarpuria was in his second year of his graduation when he got involved in criminal activities and subsequently became so strong that even the rival gangs feared him, police said.A pistol was seized from him when he was arrested, they added.