Gujarat Anti Terrorist Squad (ATS) arrested two persons for illegally exporting precursor chemicals for manufacturing fentanyl and other banned psychotropic substances by air to drug mafias in Mexico, Guatemala, and other countries, it said on Tuesday. An investigation showed that the partners of certain chemical and pharma companies in Surat had illegally procured and exported precursors for the manufacturing of the controlled psychotropic substance fentanyl, prohibited in many countries, the ATS said in a release. The accused individuals used bogus end-user certificates and fake invoices, and misdeclared the shipments to evade detection by the Customs Departments and international narcotics agencies while smuggling the chemicals via air cargo to companies in Mexico and Guatemala, it said. These substances -- 1-Boc-4-piperidone (N-Boc-4-piperidone) and 4-piperidone -- have been placed on the Red List by the United Nations International Narcotics Control Board (INCB) and also listed