According to Article 49(1)-2 in the Infectious Disease Control and Prevention Act (Preventive Measures against Infectious Diseases), to prevent the spread of COVID-19 Busan Metropolitan City has issued an administrative order making mask wearing mandatory and banning drinking alcohol and eating at night (from 22:00 to 5:00) at five parks in Busan, effective 00:00, Jun. 9 until further notice.
The administrative order includes prohibiting drinking and eating food between 10 p.m. and 5 a.m. at five parks, including Busan Citizens Park, Children's Park, Songsanghyeon Square, Busan Jungang Park and Geumgang Park, as well as requiring masks in the five parks. The gathering limit will be applied by the social distancing restrictions according to the level.
Violators could be charged with a fine of less than 3 million won and cost of disinfection.
For more details, see https://www.busan.go.kr/nhot/1491258 (Korean)