The security has been beefed up at the Uttar Pradesh Legislative Assembly after explosive powder, Pentaerythritol Tetranitrate (PETN), was found inside the assembly yesterday. The entry has been prohibited to those who do not have the Assembly pass. Everyone entering the secretariat is being thoroughly checked. According to the members, if the same security lines were being followed since the beginning then nothing like yesterday would have happened. Earlier, no passes were asked to show. Everyone needs to be supportive in the security of the Legislative Assembly, the members of the Assembly said. Meanwhile, a First Information Report (FIR) was filed against unknown persons today after explosive materials were found in Uttar Pradesh Assembly. The case has been registered under Unlawful (Activities) Prevention 2004, and Explosive Substances Act 1908. Uttar Pradesh\u2019s Inspector General of the Anti Terrorist Squad (ATS), Aseem Arun has said the discovery of the explosive powder - PETN - hinted the possibility of a terrorist activity. \u201cWe will scan through the CCTV footage and will do a detailed investigation of the spot today,\u201d Aseem Arun said. Chief Minister Yogi Adityanath has called for a National investigative Agency (NIA) probe. "The packet of the explosive was found under the chair of the Opposition's leader. It was 150 gm of PETN. 500 gm of PETN is enough to blow the whole Assembly off. This shows the severity of the situation. I suggest that everybody present in the Assembly should be investigated by the police and that the NIA should investigate into the matter," he said. "It's unfortunate that the largest Assembly of the country doesn't have a QRT," he added. Adityanath also said that this incident could be in connivance with a terrorist or militant group and that the security of the state and the country is paramount. Earlier yesterday, 60 grams of suspicious white powder was found in the UP Assembly during an ongoing session, which was later sent to forensic lab for testing.