Chitradurga, (Karnataka) June 11 : A Hindu fringe group in Karnataka has threatened Kannada litterateur B.L. Venu over his comments on the textbook revision issue in the state, police said on Saturday. A letter, containing threats and warnings, in the name of "Sahishna Hindu" was posted to his residential address on Friday. The handwritten letter contains no address. "You (B.L. Venu) have joined Socialist Democratic Party of India (SDPI), Popular Front of India (PFI) and Campus Front of India (CFI). You are supporting anti-nationals and aiding Opposition leader Siddaramaiah and former CM H.D. Kumaraswamy. You have to apologise in public for making light comments on Veer Savarkar," read the letter, police said. It also objects to the author's comments that poisonous seeds should not be sowed in the minds of children. The miscreants have asked him to advise the vicious group of 61 litterateurs in this regard, adding that there is great respect for Venu for penning a novel on the history of rulers of the region. It is also mentioned that he has joined Left thinkers, Naxals, terrorists and supporting an anti-national organization like SDPI. "Being a Hindu, you should stop raising your voice against Hindus. You need to lecture anti-nationals, political leaders and convince Muslim religious leaders," the letter said. Not taking any chances, the Karnataka Police has started investigation. Leftist thinkers, activists and writers like Gauri Lankesh and Prof M.M. Kalburgi in Karnataka were killed for their alleged "anti-Hindu" stands and remarks on Hindu Gods. /IANS