BIOSECURITY MEASURE. A staff at the Laoag International Airport implements biosecurity measures to prevent the re-entry of the African swine fever in Laoag City in this undated photo. The city government has established quarantine checkpoints to strictly monitor the transport of hogs and pork products to the city. (File photo by Leilanie Adriano) LAOAG CITY - The city government has intensified its border control to prevent the re-entry of the African swine fever (ASF) here. ASF checkpoints were established in at least five villages around 5 p.m. on Wednesday to monitor all vehicles entering the city. These checkpoints are located in the border areas of Lagui-Sail Vintar Road, 51-A Nangalisan before the Gilbert Bridge, Barangay Barit, San Mateo, and Balatong where cargo vehicles from other towns and city pass through. "The ASF checkpoints are meant to keep the city free from ASF," said Mayor Michael Keon as he ordered the proper inspection of hogs and pork products being tran