Sexual harassment on subway trains has been on a constant rise since the Seoul Metropolitan Police Agency started compiling statistics, with the number of reported cases increasing from 671 in 2009 to 1,273 in 2011.

Police said the actual number could be much higher given the number of cases that go unreported because victims are afraid or ashamed.

Now smartphones have emerged as a new tool favored by sleazy subway trawlers, who use their gadgets to secretly film the lower bodies of female passengers. They have also devised elaborate ways of fulfilling their fetish, with some installing small cameras in the tips of pens, umbrella handles or in their shoes.

Sexual harassment on the capital's public transport system happens most frequently during the morning and evening rush hours. In 2011, some 462 offenders were apprehended during the hours of 8 a.m. and 10 a.m., while 337 were caught between 6 p.m. and 8 p.m, accounting for 63 percent of cases reported last year.

Line No. 2 was the subway creeps' favorite haunt, with 583 offenses reported, followed by Line Nos. 1 and 4, with 359 and 135. Whereas the number of incidents spiked on Wednesdays (248) and Fridays (253), weekends were relatively safe with 67 reported on Saturdays and a mere 49 on Sundays.

According to a special act on sexual crimes, anyone who is found guilty of sexual harassment in a busy public place is subject to a prison term of up to one year, or a fine of up to W3 million (US$1=W1,163). If caught taking pictures or recording footage using a video camera, the offender can be jailed for a maximum of five years or fined up to W10 million.

Although the Seoul Metropolitan Government had planned to introduce women-only cars, the plan was indefinitely postponed due to fierce opposition. Men's groups complained that it was unfair that a few bad eggs could cause all men to be viewed and treated as potential sex offenders.

Instead, the city government plans to install CCTV cameras in trains operating on Line Nos. 2 and 7 in April to raise awareness about the seriousness of the issue and crack down on it. Meanwhile, the so-called subway sheriffs, who began their duties last September, are also tasked with watching out for potential offenders as well as illegal vendors to maintain order both on trains and at stations

The police and the Seoul subway authority are advising women on how to prevent or react to sexual harassment. They urge them to place their bags behind their lower back when they climb steep steps or ride long escalators and react immediately to even the slightest physical contact.

They are also advised to use carriages close to the front or rear of the train as most shady characters who like to grope or film women on the subway tend to avoid those carriages because it is not easy to move to another carriage when they are confronted.