The National Investigation Agency (NIA) on Thursday said it has arrested an arms supplier involved in the murder of RSS leader Ravinder Gosain in Ludhiana in Punjab.An NIA official told IANS: "The agency has arrested Malook who is accused of providing weapons to the assailants who killed Gosain." The arrest was made during a joint operation by the NIA and the Uttar Pradesh Special Task Force on Wednesday.On Sunday, a team of NIA and Uttar Pradesh Police was attacked by a mob when it raided Nahali village in Ghaziabad district in pursuit of the accused.Constable Tahzib Khan suffered a leg injury when the mob stoned the raiding team and even fired at them. The mob also damaged an official vehicle.The NIA was also looking for Iqbal, a resident of Hapur district for giving shelter to Malook.NIA teams are reportedly searching for him in the National Capital Region.On Tuesday, Pahar Singh, 48, was arrested from his residence in Meerut on charges of supplying a home-made weapon to the main accused, Hardeep Singh. The NIA earlier had arrested Ramandeep and Hardeep Singh for the murder of Gosain, 60, who was shot dead on October 17 near his house while returning after a morning RSS meeting.The NIA took over the case from Punjab Police.