Security around sensitive and crowded spots, including Har Ki Pairi has been tightened, Inspector General of Police G S Martolia, in charge of the security for the mela, said.
Four youths with suspected terror links who were allegedly conspiring to strike in the mela area were held by a joint team of Delhi Police Special Cell and Uttarakhand police on Tuesday night from Manglour town in Haridwar district.
IG Martolia said all vehicles coming to Haridwar besides hotels and lodges in the district are being checked to keep a tab on dubious people.
Visitors to temples are on CCTV surveillance and senior police officials are patrolling the mela areas 24x7, he said.
A special vigil is being kept around vital installations and at points bordering the neighbouring states like Uttar Pradesh and Himachal Pradesh with patrolling and frisking being intensified, he said.
Bomb disposal squads and intelligence personnel are maintaining a constant vigil in the mela area and all intelligence inputs received are being analysed, he said.
Senior police officials, including IG Martolia, later visited Laksar railway station near Roorkee and all the check posts and police stations between Laksar and Haridwar to take stock of security arrangements there, a release from DIG Ardh Kumbh's office said.
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