"A strict screening of the people crossing the border and entering India is being undertaken by the Sashastra Seema Bal (SSB)", DIG, SSB RS Shekhawat told PTI.
All religious places here are being closely monitored following reports that Pakistan's ISI was using them as a base for infiltrating the country and carrying out anti-national activities, Shekhawat said.
Thousands of people cross into India from the porous borders in Shravasti, Balrampur, Siddharth Nagar, Maharajganj districts in the eastern part of Uttar Pradesh every day.
"An alert has been sounded in the border areas and a strict vigil is being maintained," he said.
Security agencies have been asked to ascertain the identities of people who cross over through the border to prevent Maoist activities in the area, he said.