Criminal activities such assmuggling of contrabands, infiltration and dacoity along Tripura's 856-km international border with Bangladesh have sharply reduced since the implementation of the nationwide lockdown in March, officials said on Friday.He said smuggling of psychotropic substances has come down to "almost nil" due to the curbs in place as transportation of contrabands from other states have come to a grinding halt."We have observed that border crimes have sharply reduced after the lockdown was announced by the Centre. Smuggling of contrabands like 'yaba' tablets or fensidyl cough syrup was rampant across... Sonamura area of Sipahijala district and Belonia area in South Tripura district, but it is almost nil now," an official of BSF Tripura Frontier here told PTI.The official said other crimes like smuggling of cattles and infiltration have also gone down since the state government deployed personnel of the Tripura State Rifles (TSR) as the second line of defence after the BSF."Bangladesh is also now very alert, so that no one can enter inside their territory. They have deployed army along the border," the official said.The Tripura government has also alerted the village heads in the bordering areas.A total of 24 Border Security Force (BSF) personnel tested positive for COVID-19 in Tripura on Thursday, taking the number of novel coronavirus cases in the state to 88, Chief Minister Biplab Kumar Deb had said."We are maintaining social distance on duty and regularly sanitising the border out posts (BOPs)," the BSF official said.