JAKARTA, Indonesia — Indonesia’s number of confirmed coronavirus cases surpassed 20,000 as the world’s most populous Muslim nation is entering a critical period in its fight against the COVID-19 outbreak during its most important Islamic holiday.

Health ministry official Achmad Yurianto announced 973 new infections, the biggest daily increase since the start of the pandemic, bringing the total number of confirmed cases to 20,162.

Yurianto said the outbreak has been growing significantly in the East Java province in the past 24 hours with 502 confirmed cases, which has contributed the most to the country’s biggest single-day spike on Thursday.

Indonesia’s COVID-19 Task Force chief Doni Monardo told a news conference the virus spread has been growing at its fastest speed during the last nine days as the country is entering a critical moment before and after its Eid al-Fitr celebration to mark the end of the fasting month of Ramadan.

Ramadan exodus was banned this year to contain the spread of the disease, but Monardo said some people had managed to leave big cities.

Monardo said his team is asking help from the military and the police to prevent arrivals in the capital, Jakarta until a full reopening of the capital.