Seoul, June 22 : In-flight disturbances and other illegal acts on board have increase significantly this year in South Korea as more people have gone on overseas trips since the lifting of Covid-19 restrictions, government data revealed on Thursday. According to the data from the Ministry of Land, Infrastructure and Transport, 159 such cases were reported between January and April, compared with 85 cases in the same period in 2021 and 264 cases throughout all of 2022, reports Yonhap News Agency. Of the total, 130 cases involved smoking, followed by 15 cases of verbal violence and other disturbances, eight cases of drinking-related unruly behaviour and two cases of behaviour leading to sexual humiliation, the data showed. In a recent incident, a passenger opened the door of an Asiana Airlines plane just before landing at Daegu International Airport. Another similar incident took place earlier this month when a teenager attempted to open a plane door during a flight. /IANS