Indonesia is imploring its citizens not to panic and to practise social distancing and self-isolation, as the country's health system strains under the weight of rapidly rising infections.
The country reported 105 new cases of coronavirus on Wednesday, taking the national tally to 790, and three new deaths, taking the death toll to 58 people.
Ascobat Gani, a public health economist, warned that "maybe we will follow Wuhan or Italy. I think we are in the range of that" according to Reuters.
A study by the London-based Centre for Mathematical Modelling of Infectious Diseases suggested the true number of infections in the country may already be 34,300 people.
Eight doctors have died already in Indonesia and some physicians have taken to wearing rain coats because of a shortage of protective gear.
Thailand's government declared a state of emergency on Wednesday that will run until April 30. The country is already in partial lockdown, with shops that don't provide essential services closed and tough restrictions on travel.
The country reported 934 cases including 107 new infections and the death toll remained at four.
Malaysia has now reported 1796 positive cases, with the number of cases rising by 172 people on Wednesday and the death toll rising by one person to 16.
A movement control order on Malaysians has been extended through until April 14. The order restricts people from leaving their homes and from leaving the country, while foreigners are banned from entering Malaysia. Prime Minister Muhyiddin Yassin asked people to remain calm.
The Philippines has reported 636 confirmed cases and 38 deaths, the second-highest in south-east Asia, while Vietnam has reported 134 infections, including 31 foreign citizens.
Myanmar has finally reported its first three cases of coronavirus, confirming its first cases on Tuesday - weeks after most other south-east Asia nations.
The number of cases in Singapore his risen to 558 infections, up from 509 on Tuesday.