Prime Minister Narendra Modi on Saturday averred that stringent punishment will be meted out to those who were responsible for the murder of a BJP activist in Purulia, as also in all other parts of the state."In Purulia, one more of our activists was killed. All our leaders and I stand by his near and dear ones. I want to assure all our office-bearers, voters and children that justice will be done for the atrocities."The law will punish those who committed the atrocities, as also those who conspired. These people will get stringent punishment," the Prime Minister said while addressing an election meeting in this town of Dakshin Dinajpur district.Modi asked the crowd whether the game of intimidation, loot and corruption should continue in Bengal.Yet again calling Chief Minister Mamata Banerjee "speedbreaker didi", he said: "Shouldn't she get stringent punishment?"In all his public meetings in Bengal of late, Modi has been taking digs at Banerjee by calling her 'speed-breaker didi' for slowing down the development of the state.Modi said neither history nor the future would pardon "Mamata didi" for what she has done.The body of 22-year-old Sishupal Sahis, a BJP activist and son of a party Gram Panchayat member was on Thursday found hanging from a tree in Purulia district.BJP leader Mukul Roy claimed that the youth has been murdered and indirectly accused the state's ruling Trinamool Congress for the killing.