The National Police Agency said Thursday it will completely ban smoking in police station detention facilities across the country starting April 1.

Detainees are currently permitted to smoke one or two cigarettes in exercise areas on weekdays under the supervision of police officers. The authorities let smokers and nonsmokers exercise during different hours.

Some detainees have complained about the lingering smell of tobacco and of second-hand smoke, the NPA said.

Smoking is already prohibited in prisons and detention centers for people awaiting trial, as well as in police interrogation rooms.

A smoking ban is already in place in police detention facilities in Tokyo and Okinawa.