LUCKNOW: In a major security breach, a dangerous plastic explosive was found in the Uttar Pradesh Assembly, Chief Minister Yogi Adityanath today informed the House.An emergency meeting was called to discuss the recovery of the explosive on July 12.As soon as the House met, the chief minister informed that a white powder was found wrapped in a paper close to the seat of the Leader of the Opposition Ram Govind Choudhry. The explosive was found by the cleaning staff.After the powder was sent for FSL examination, it was found to be a dangerous plastic explosive PETN (Pentaerythritol tetranitrate), he said.The dog squad failed to detect the explosive.Terming it as a conspiracy, he said the NIA should probe the matter.Stressing that there should be no compromise on security, the chief minister said joint efforts were needed to ensure this.It is a "dangerous tendency that the security of the assembly has been breached when the House is in session," he said."So far the government was worried about security outside the assembly now this has become a more serious matter," he said.He appealed to Speaker Hriday Narain Dixit to ensure police verification of the assembly staff because security of over 500 MLAs and MLCs was at stake.