PATNA, Jan. 29 -- Recovery of an empty cartridge bearing Urdu letters from the spot of an encounter between Maoists and security forces in the Ratanpur Mines Forest area on the border of Nawada (Bihar) and Koderma (Jharkhand) districts on Thursday last has once again led the police to suspect links between the left-wing extremists in India and foreign militant groups or intelligence agencies, especially the ISI....