Four disc jockeys, who recently arrived in Taiwan to perform at a music concert in Taipei, have each been fined NT$10,000 (US$351) for breaking quarantine rules, the Central Epidemic Command Center (CECC) said Saturday.

During their mandatory 14-day quarantine period, the four individuals slipped out of their separate rooms at a quarantine facility and met in a common area to eat and rehearse for the show, CECC spokesman Chuang Jen-hsiang (莊人祥) said at a press briefing in Taipei.

They obviously disregarded the "one room per person" rule for quarantine in Taiwan and therefore have been fined NT$10,000 by the Taipei City Department of Health, under Article 58 of the Communicable Disease Control Act, he said. Authorities became aware of the violation when a video was uploaded on social media, showing the four DJs gathered in an indoor area, wearing no masks, Chuang said.

Yu Tsang-hua (余燦華), head of the disease control section of the Taipei Department of Health, said the four foreign nationals arrived in Taiwan on Oct. 28, and were in quarantine for 14 days until Nov. 12. They are each required to pay NT$10,000 within seven days of receiving their penalty notice, and failure to settle the fine will result in the case being handed over to the Administrative Enforcement Agency, Yu said.

The DJs are in Taiwan to perform at a concert dubbed "Road to Ultra: Taiwan 2020," which is being held at Dajia Riverside Park Saturday evening. While Chuang and Yu did not name the visitors who broke quarantine, the event's official website lists four DJs—Kayzo, Vini Vici, Slander, and Alesso—who it said were invited to Taiwan to perform at the concert.