The three persons have been bludgeoned to death in separate incidents reported from Mavdi, Munjhka and Bhaktinagar railway station areas in the last 45 days. All three were repeatedly hit with stones by the killer, who later called up their families from the victims' cell phones to inform that he had killed them. The city police are still grappling for clues to solve the murders of three persons by an person who is being described as a 'stone killer.' The deceased were identified as Sagar Mevada, who was found murdered near Bhaktinagar railway station, Pravin Barad, a resident of Munjhka and Vallabh Rangani who was killed while on morning walk on June 6 in Mavdi. Police have announced a cash reward of Rs two lakh for anyone giving information about the 'stone killer.' Based on a sketch prepared from the faint image seen in CCTV footages, police have questioned nearly 50 people. This, however, has been of little help. Police also questioned two persons - Badal and Hariya -- who were earlier arrested for bludgeoning a man to death with stones. But this has also not yielded any results.