Indian Police will send 600,000 text messages to men who have sexually harassed or taunted women in the past to remind them to be on their best behaviour on New Year's Eve. The message will be sent to former offenders in the northern state of Uttar Pradesh and says: "You and your phone are still under observation. Hope your conduct is upright now. We wish you a Happy New Year."

Along with the thinly-veiled threat to "Eve-teasers" – which is an Indian term for men who sexually harass women – police will send half a million victims of sexual harassment reassuring messages saying the police are there to help.

Uttar Pradesh comprises of Kanpur and Agra and is India's most populous state with 200 million of the country's 1.2 billion population living there. Police officers say the text messages are a deterrent in a state where sexual harassment is seen as a major problem although reported cases have gone down from 1,491 in 2013 to 551 this year.

"The message to Eve-teasers, or pesky callers, is a reminder that the police have their record. It is meant as a deterrent. We are trying to tell them that any attempt to trouble women and create mischief will prompt strict action," senior police officer Navniet Sekera said, Al Jazeera reported.

India was forced to confront problems of sexual harassment and violence after the brutal gang rape of a 23-year-old medical student on a bus in December 2012. In the weeks that followed thousands of woman took to the streets to try to secure more rights and protection for women.

But Kavita Krishnan, secretary of All India Progressive Women's Association (AIPWA), said that the text message idea would have little effect. She said: "It's an image-building exercise, a fairy-tale being spun out by the police.

"Every day women face sexual harassment. It's a nightmarish situation for them because women are afraid to speak. Incidence of violence and custodial violence is a big problem in UP (Uttar Pradesh)."