Patna: The opposition BJP on Thursday demanded that illegal slaughter houses flourishing in Bihar should be closed in line with the neighbouring state of Uttar Pradesh.Leader of Opposition Prem Kumar raised this issue in the state assembly to demand immediate closure of illegal slaughter houses in Bihar and asked for the cancellation of licences of all slaughter houses in the state."We have demanded closing down of illegal slaughter houses and cancellation of licences issued for these in the state," Prem Kumar told media here.He said the BJP is keen on a beef-free Bihar to ensure protection of cows. "Bihar should ban beef in line with Maharashtra."But Bihar Animal Husbandry Minister Awadhesh Kumar Singh rejected the BJP's demand by saying that there are no illegal slaughter houses in the state."BJP leaders should talk about development instead of playing politics of slaughter houses," he said.According to officials, cow slaughter is banned in Bihar as per a 1955 law. But it continues unabated due to a flaw in the law that permits killing of a cow, buffalo or bull that is more than 15 years old or diseased. The violation of this provision invites a maximum jail term of six months and a fine of Rs 1,000.In the 2015 Bihar assembly polls, BJP's top leaders, including Prime Minister Narendra Modi and party president Amit Shah, tried to play the beef issue during their campaign to polarise voters, but the appeal failed to move them.