The number of crimes that threaten flight safety has been on the rise in recent years, a lawmaker’s report showed Wednesday.

According to Rep. Lee No-keun of the ruling Saenuri Party, over 40 cases in violation of the aviation safety regulations were caught last year, which was triple the figure of 2013.

In-flight smoking was the most common violation, accounting for 80 percent. Most of them were caught while smoking in the restroom, the report said. By law, anyone smoking in the airplane can be fined up to 5 million won ($4,200).

A total of 12 cases were related to affrays, while six other cases were sexual crimes, including sexually harassing flight attendants or masturbating in the seats.

Meanwhile, another report by Rep. Kang Seok-ho of the same party showed that crime occurrences surged not only in the flights, but also at the airport.

About 1,000 violations were caught at Incheon International Airport over the last three years, with theft accounting for 30 percent of the total.

Thefts continue to rise, with over 60 cases already being reported this year, double that of 2010, Kang said. The apprehension rate for theft, however, remained around 40 percent over the past six years, the lawmaker added.

The number of lost items also rose every year, with the return rate staying under 50 percent.

The number of lost belongings reached around 30,000 last year. Of them, only about 40 percent were returned to owners.

As part of the efforts to raise the collection rate, the airport police has recently expanded the lost-and-found office and started to offer delivery of lost items through a parcel service.

By Lee Hyun-jeong  (rene@heraldcorp.com)