The acting chief of an umbrella labor union was questioned by police as a suspect on Friday over a series of large rallies held in downtown Seoul in violation of quarantine protocols.

The Jongno Police Station in Seoul grilled Yoon Taek-geun for three hours from 10 a.m. He has been leading the Korean Confederation of Trade Unions(KCTU) since chair Yang Kyung-soo was arrested in September.

Yoon was booked on charges of violating laws on assembly and demonstration, obstruction of traffic, and infectious disease prevention by holding labor rallies on October 20 and November 13. Over 20-thousand people reportedly gathered for the rallies.

Speaking to reporters at the police station, Yoon said the protests were to convey pressing labor demands and accused the Moon Jae-in administration of a witch hunt over its failed quarantine measures. He called on the government to stop the summons and listen to the workers

Police have so far questioned ten figures as of Thursday while 20 individuals have been booked.