Patna: The Bihar Special Task Force (STF) has arrested 146 persons involved in various illegal activities along the Indo-Nepal border between Jan and April 22 this year, STF deputy inspector general of police Neeraj Kumar Singh said on Monday.Addressing a press conference at the Police Headquarters at Sardar Patel Bhawan, Singh said the Bihar Police has constituted a special joint force with the Sashastra Seema Bal (SSB) and local police to tighten security and increase surveillance along the porous international border.He said four such joint units have been formed so far, each comprising 40 personnel drawn from the STF, SSB and local police stations. “These teams have been deployed in highly sensitive stretches spanning 13 sub-divisions and 69 police stations along the Indo-Nepal border. They are maintaining round-the-clock vigil to prevent cross-border crimes,” the DIG said.Singh revealed that 128 cases have been registered during the period for smuggling of narcotic substances, fake Indian currency notes and other illegal activities. During raids and searches, the joint teams seized 95 kg of doda, 590 kg of ganja, Rs2 lakh in cash, cough syrup, opium and several other banned substances.The STF DIG said districts such as Sitamarhi, Bettiah, Madhubani, Bagaha, Supaul, Araria and adjoining areas have been identified as particularly vulnerable to trans-border crimes due to their proximity to Nepal and the open nature of the border.Singh further said encroachments within a 15-km stretch of the international border have been removed as part of intensified enforcement efforts. “Comprehensive verification of commercial establishments operating in the border areas is being conducted. In addition, authorised money exchange centres have been set up by the govt to curb illegal currency transactions,” he added.Highlighting the seriousness of the issue, Singh said the Indo-Nepal border is frequently used for smuggling of fake currency notes, skins and body parts of endangered animals, cattle, urea, ganja, opium, doda, narcotic chemicals and other prohibited items. “The special task force, along with central and state agencies, is maintaining constant surveillance to dismantle smuggling networks,” he said.Meanwhile, STF DIG Sanjay Kumar said STF teams have also been deployed to West Bengal to assist local authorities in ensuring peaceful conduct of elections. He added that the STF has played a key role in arresting Bihar-based criminals involved in offences committed in other states.