Indonesia confirmed its 100,000th coronavirus case on Monday as the Red Cross warned that the health crisis in the world's fourth most populous country risked "spiralling out of control".

The vast archipelago -- home to more than a quarter of a billion people -- has been recording 1,000-plus new infections daily after relaxing movement restrictions this month in a bid to head off a collapse of Southeast Asia's biggest economy.

As of Monday, Indonesia had reported a total of 100,303 COVID-19 cases and 4,838 deaths. But with some of the world's lowest testing rates, the true scale of its toll is widely believed to be much greater. Dozens of frontline doctors have succumbed to the deadly respiratory disease while health officials have warned that hundreds of children may have also died from it -- as many suspected virus victims are buried without testing.

The country of nearly 270 million is among the worst hit in Asia by the pandemic, with cases in all of its 34 provinces, including the remote Maluku islands and easternmost Papua. There have been protests against distancing rules and even testing in parts of the country, including the holiday island Bali.

And critics have slammed widespread signs of Indonesians becoming less vigilant under the government's so-called "new normal" policy. They point to re-opening offices in the capital Jakarta as a major culprit in the surge, while restaurants, shopping malls and tourist attractions are also swinging open their doors around the country.

"We are intensifying our efforts to educate the public about the importance of changing their behaviour for good by physical distancing, wearing masks and practising good hygiene," the Indonesian Red Cross said Monday, adding that it has enlisted some 7,000 volunteers nationwide. "This calls for a unified, unprecedented, large-scale effort to reach all parts of society, in every corner of our country," it added.

President Joko Widodo has called for higher testing rates and a tougher response, including threats to reshuffle his cabinet if ministers don't do a better job at fighting the crisis. But his government has cancelled a daily COVID-19 press briefing that was seen as crucial for informing the public and questioning its handling of the outbreak.

Widodo, better known as Jokowi, has also been criticised for a slow response to the crisis and earlier comments that he feared making information about the virus public would spark widespread panic among the huge population.

Indonesia reported its first confirmed virus case in March. "The 100,000 cases today should alert the government that it has to be more serious in handling the pandemic," said Indonesian Doctors' Association spokesman Halik Malik.

"People have become less vigilant in recent months because of the government's narrative about the 'new normal'. It's misleading and could prompt people to think the virus is under control but, in fact, it's not."