A top activist of the Maoist-backed PCPA who was named as one of the three key accused in the May 28 Jnaneswari Express derailment was arrested today near Jamshedpur by a joint police team from West Bengal and Jharkhand. <br/><br/>SP Abhisekh Kumar said, Bapi Mahto and his cousin Vimal Mahto were picked up from a guest house at Adityapur in the Saraikela-Kharswan district adjoining Jamshedpur. He said, Vimal was arrested for harbouring Bapi. <br/><br/>The arrested will be produced in the Chief Judicial Magistrate's Court in Saraikela-Kharswan district to procure order for their transit remand.<br/><br/>The breakthrough came three days after the CBI named Bapi and Umakant Mahto, senior PCPA activists, and PCPA<br/>convenor Asit Mahto as the main accused and announced a reward of one lakh rupees each for information leading to their arrest.