ATHENS, Greece — Municipal authorities say operators of a beach bar near Athens have been fined 20,000 euros ($22,600) and had their license suspended for two months after hundreds of revelers allegedly packed into the site late Wednesday in violation of government health restrictions.

The incident occurred days after another beach bar was also handed a 60-day shutdown order on the popular resort island of Mykonos which recently opened up for tourism.

Greece will officially launch its tourism season Monday with relaxed checks for travelers at airports in Athens and the second-largest city, Thessaloniki, before other airports reopen on July 1. But authorities have promised to take a tough line with businesses that ignore health restrictions while remaining ready to impose localized lockdowns to contain new infection clusters.

Weeklong restrictions were imposed Thursday in the northern region of Xanthi following a spike in cases, authorities said. The Health Ministry also reported 20 new cases of COVID-19 during the latest 24-hour reporting period, raising the confirmed total to 3,088 while the death toll remained unchanged at 183.