Mayors also announced plans to impose a night curfew in Metropolitan Manila, home to more than 12 million people. Residents have been asked to stay home except for work and urgent errands under monthlong restrictions that took effect Sunday.

The citywide quarantine means the suspension of domestic travel by land, air and sea to and from the capital region. Large gatherings like concerts, movies and cockfighting will be prohibited and most government work in executive department offices will be suspended in the metropolis. School closures at all levels were extended by a month.

President Rodrigo Duterte announced what he billed a "general community quarantine" of the entire metropolis on Thursday. Officials issued guidelines on Saturday after confusion over the drastic moves set off panic buying in supermarkets and prompted many provincial residents to stream out of the metropolis, fearing they would be stranded in the capital.

Officials said the temporary restrictions will not amount to a lockdown of the capital because many workers and emergency personnel like medical staff will be able to enter and leave the capital. Residents can move within the metropolis on their way to work or for urgent errands, including medical emergencies, officials said.

Movement of cargo and food shipments will continue unhampered, they said.

Nevertheless, by early Sunday truckloads of policemen and soldiers spread to the peripheries of the metropolis and started to man checkpoints on major entry and exit points. The coast guard announced a no-sail policy in Manila Bay but said cargo ships, fishing boats, government vessels and some foreign ships were exempted from the ban.

A copy of the guidelines said the movement of people in the Manila metropolis "shall be limited to accessing basic necessities and work."

"If you'll go to work, go. If you need to go out for medical treatment, go. If you'll buy food, go, but other than that, stay home," Interior Secretary Eduardo Ano told a news conference on Saturday. "We should practice social distancing."

Philippine health officials reported dozens of new cases infections Saturday, bringing the total number of COVID-19 cases in the country to 111. Eight of the patients have died.

While the virus can be deadly, particularly for the elderly and people with other health problems, for most people it causes only mild or moderate symptoms, such as fever and cough. Some feel no symptoms at all and the vast majority of people recover.

Ano said the 8 p.m. to 5 a.m. curfew, which was proposed by 17 mayors, would apply to nonessential trips and leisure gatherings like parties, family reunions and concerts. Stressing the urgency of the move, he cited the case of Italy, where he said the numbers of COVID-19 infections and deaths alarmingly spiked because effective containment steps were not put in place early.

Police Lt. Gen. Guillermo Eleazar said cities and towns would enforce the curfew once their separate councils have authorized it in the next few days.

Ano warned that infections may exponentially increase to several thousand in the Philippines in five months if effective containment actions are not set in place. He told The Associated Press that it's one of the worst-case scenarios drawn up by the government along with World Health Organization experts.

Metropolitan Manila police chief Maj. Gen. Debold Sinas has threatened to arrest people who don't comply with the new restrictions. But a prominent human rights lawyer, Jose Manuel Diokno, said law enforcers could not arrest anyone for resisting emergency health restrictions.

Under Philippine law, police can arrest people without a warrant only if they have committed or are about to commit a crime, Diokno said.

The 74-year-old Duterte himself was tested for the virus on Thursday after he met Cabinet officials, who said they were exposed to people who tested positive for the coronavirus. Duterte tested negative, according to his spokesman.