While couples thronged restaurants, pubs, cinema halls and parks in cities and towns to celebrate the day -- which coincided with the Hindu festival of Shivratri this year -- police said they had taken measures to ensure that there was no violence against courting couples.
For several years now, far-right groups have been protesting against the festival which they believe celebrates western values and violates Indian tradition. Police said some people had been detained in a bid to prevent violence.
The Vishwa Hindu Parishad claimed it had asked the people to leave the spot, a popular haunt of the young, and that its members did not attack anyone.
The police reached the waterfront and took the men into custody for allegedly threatening the couples.
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In some videos -- the veracity of which could not be independently established -- people carrying saffron flags and holding sticks were seen forcing couples to leave the spot.
In Bhubaneswar, the police took 30 activists of the Kalinga Sena into preventive custody, apprehending trouble by the local outfit.
The activists were detained at Baramuda near the Kalinga Sena office when they were preparing to visit parks apparently in search of courting couples.
The police also deployed extra forces at malls and public places.
"We burnt effigies of (Saint) Valentine during the protests," said Kailash S, a Sena representative.
In Hyderabad, members of the Bajrang Dal staged demonstrations against V-Day celebrations and barged into a few pubs and restaurants in different parts of the city, demanding that there be no special programmes to mark the day.
In Delhi, a group of traders offered roses to passersby near municipal offices to draw their attention to problems posed by an ongoing sealing drive in the city.
The traders held placards and presented roses to people as part of the 'My Valentine-My Shop' protest, organised by the Confederation of All India Traders (CAIT).
At a call-in programme on the third anniversary of the Aam Aadmi Party government, Kejriwal said, "Nafrat ka jawab nafrat nahi, nafrat ko pyar aur mohabat se counter kiya ja sakta hai (Do not counter hatred with hatred, but with love)".
His message was in reply to a Delhi University student who wished the chief minister a happy Valentine's Day.
The Congress also jumped on to the V-Day bandwagon, with a satirical message on Twitter.
The post showed the colourful sketch of a young girl and a boy holding a heart each and sitting dolefully on the two ends of an enormous moustache sported by a man with a saffron scarf draped around his neck.