Philippine President Rodrigo Duterte has ordered nearly 60 million residents on the country's largest island to stay home for a month as part of a wider lockdown in a bid to contain the spread of the coronavirus.
Responding to a surge in cases in nearby Malaysia, the prime minister has also imposed travel restrictions, directing most businesses except for shops be closed, and banned foreigners.
In the Philippines, an "enhanced community quarantine" now covers the main island of Luzon - home to the capital Manila and more than half the country's population.
Mass public transport as well as work in public and private offices have been suspended, except for establishments providing basic goods and services.
"Everyone will stay at home, leaving their houses only to buy food, medicines and other basic (goods) necessary for survival in the coming days," Duterte said in a televised address on Monday.
"Don't be scared about this. You can go out to buy food."
People who need to travel outside the Philippines were given 72 hours to leave Luzon, while incoming passengers are allowed to enter as long as they do not come from countries with COVID-19 infections.
All travellers will be subjected to quarantine upon arrival.
There are 142 confirmed COVID-19 cases in the Philippines, including 12 deaths.
Meanwhile Malaysian Prime Minister Muhyiddin Yassin said that from Wednesday until the end of the month, all businesses should be closed except for supermarkets, public markets, grocery stores and convenience stores.
Malaysians will not be permitted to travel abroad over the two-week period, and foreigners will not be allowed to enter, the prime minister said in an address to the nation late on Monday.
Malaysia reported 125 new cases of coronavirus on Monday evening, taking the country's total to 553.
Some 338 cases have been traced to an Islamic ceremony held in Kuala Lumpur's outskirts in late February that was attended by an estimated 15-16,000 people and which spawned cases among worshippers from Brunei, Cambodia and Singapore.
Earlier, Religious Affairs Minister Zulkifli Mohamad Al-Bakri said activities in mosques, including Friday prayers, will remain suspended for 10 days.
Neighbouring Singapore recorded its biggest single-day increase in coronavirus cases on Monday, with the 17 new diagnoses announced by the Health Ministry pushing the city-state's total to 243.
China's downward trend of new infections continued, with 16 new coronavirus infections and 14 new deaths reported over the past day.
South Korea reported its lowest daily increase of new cases in almost three weeks, with 74 new infections recorded and no new deaths, according to figures released by the health authorities.