South Korean police are mulling deployment vehicles equipped with decibel meters at protests in order to determine whether or not the rallies exceed the legally permitted noise level, local media reported Friday.

According to local newspaper Chosun Ilbo, the National Police Agency's plan is to convert one of its trucks to fit a noise-measuring device to be used at protests this year, and to acquire another one of these vehicles by next year. The NPA is currently requesting an extra budget to purchase the trucks.

South Korean law prohibits protests from emitting excessive noise in residential areas, or around schools, hospitals and public libraries. If the average noise level for a 10-minute span exceeds 65 dB, or the noise level spikes to 85 dB or above three times within one hour, authorities can restrict the protest.

Police officers take part in a training exercise to forcibly break up illegal protests in Seoul on May 25. (Seoul Metropolitan Police Agency)

Police first used a noise-measuring vehicle it rented from a private company at a March 25 protest by the Korean Confederation of Trade Unions.

The police's move to acquire a noise-measuring truck comes after President Yoon Suk Yeol's recent vow to take strong measures against illegal protests. Last month, Yoon said in a Cabinet meeting that the government will not tolerate any illegal activities at rallies, criticizing what he called lack of supervision from the previous Moon Jae-in administration.

Following Yoon's comment, the ruling People Power Party and the Yoon administration said they will review revising a law that would restrict protests by groups that have been found guilty of illegal activities in the past. The announcement sparked complaints from local pundits, who said that the move potentially violates constitutional rights to freedom of assembly and association.

The National Police Agency has also announced it will revive exercises on forcibly breaking up illegal protests. The exercises had been discontinued after a 68-year-old protestor was fatally injured by a police water cannon in 2015.