He Ping, an official at China’s Ministry of Justice, told reporters at a daily briefing Friday that officials have been fired after more than 500 cases of the newly discovered virus were diagnosed in five prisons across three Chinese provinces, including Hubei, the epicenter of the outbreak. No deaths have been reported, he said.

The first cases of the new coronavirus, known officially as COVID-19, emerged back in December in Wuhan, the capital of Hubei province. Chinese authorities have since placed the city under lockdown, but containment of the illness remains a struggle.

As of Friday, China’s National Health Commission said it had received 75,465 reports of confirmed cases and 2,236 deaths on the Chinese mainland.