Police and railway operators in and around Tokyo have jointly launched a two-week campaign against groping on trains.

Police say that the instances of groping on trains tends to increase around this time of year. Last year, police uncovered about 240 such cases in Tokyo alone.

At Shibuya Station in Tokyo, about 50 police officers and railway company officials called on passengers to be on the alert, and distributed flyers introducing a new anti-groping smartphone app.

The app, called DigiPolice, was developed by the Tokyo Metropolitan Police Department. It can display a written message asking other passengers for help, and blast a voice telling the molester to stop.

It also has a function to display a message to ask potential victims whether they are being groped so that other passengers can help them.

Takei Toru, the head of the Shibuya police station, said he would like to build an environment to prevent molestation with the help of not only victims, but also people around them.