MANILA - President Rodrigo Duterte placed the entire main Philippine island of Luzon under "enhanced community quarantine" on Monday (March 16) as measures to contain the new coronavirus by sealing the capital's borders failed.

"Upon further study of worldwide trends and measures and the need for extreme caution during such a time as this, I have come to the conclusion that stricter measures are necessary," Mr Duterte said in a public address.

He said he decided to place Luzon "under quarantine" until April 13 because "I can't go into a guessing game. I have to act".

Luzon makes up a third of the Philippines, with a land area as large as South Korea and a population of over 55 million. Metropolitan Manila, the capital region, is in Luzon.

The measures are among the strictest in place in Asia, as the Philippines grapples to contain an outbreak that has seen confirmed cases rise to 142 - from only three cases 10 days ago - with 12 deaths.

Everyone on Luzon is now on "strict home quarantine".

"Everyone will stay at home, leaving their houses only to buy food, medicine and other basic necessities for survival in the coming days," said Mr Duterte.

Most companies were told to wind down, except for banks, money transfer services, utilities, telcos, and outsourcing and export firms.

Public markets, supermarkets, groceries, convenience stores, clinics, hospitals, pharmacies and drug stores will also remain open.

Most malls have decided to shut down, but will keep their supermarkets and pharmacies open.

Restaurants will be limited to takeouts and deliveries.

Buses, jeepneys, trains and all mass public transport have been grounded. But movement of cargoes will be unimpeded.

"We cannot really control the contagion. We want it to be perfect. But there will be downsides," said Mr Duterte, as he sought to allay unease over these measures.

He urged companies to consider an early release of the 13th month pay of their employees to help tide them over, and landlords to suspend rent and leases. The government would also extend financial help to the most affected small and medium-size businesses, he added.

The government stepped up its efforts to contain the virus after the lockdown imposed on Metropolitan Manila buckled on Monday morning, its borders overrun by massive numbers of people and vehicles coming through.

At many key junctions, traffic ground to a near standstill.

Commuters, pedestrians and motorists swarmed roads leading to Metro Manila like bees as they squeezed their way through dozens of checkpoints set up to enforce the lockdown.

Metro Manila has a population of nearly 13 million. At day time, that number swells by three million as those living in the suburbs head to the capital for work.

The government had allowed them to cross into Metro Manila.

President Duterte's spokesman, Mr Salvador Panelo, admitted that lockdown enforcement measures were failing and tougher actions were needed.

"Today, three million entered Metro Manila. We had a problem… We really have to assess whether what we're doing is effective, or we may need a stricter implementation," he told reporters.

Metro Manila, which spans 16 cities, underwent a sweeping, month-long lockdown on Sunday (March 15) to prevent the spread of the coronavirus to other parts of the Philippines.

Individual cities have also passed ordinances imposing an 8pm to 5am curfew.

There are currently 140 confirmed cases of Covid-19, the disease caused by the virus, in the Philippines. Twelve of those infected had died.

The checkpoints, undermanned and lacking in thermal scanners, were overwhelmed on Monday morning, as millions who live in suburbs just outside Metro Manila began marching towards their workplaces inside the capital.

Along at least two major highways leading to Metro Manila, bus passengers were being asked to disembark, as police and health personnel scanned their body temperature and checked their identification papers.

The process was long and cumbersome, causing a traffic jam several kilometres deep.

At an intersection in Cainta town, just east of Manila, a district health worker stood on a sidewalk to randomly check pedestrians for fever and remind them to wear masks. Most ignored her.

On the road, three policemen did their best to flag as many vehicles as they could. But they waved through most of them.

At one checkpoint, in Zapote Road, in Las Pinas city, south of Manila, enforcers simply gave up when their thermal scanner ran out of battery.

A man was arrested for insisting he be let through a checkpoint. Another was turned back because his granddaughter, who was with him, did not have an ID.

Along Edsa, Metro Manila's main thoroughfare, tens of thousands were seen waiting by the roadside.

There were so few buses on the road, it appeared as if the transport companies had launched a successful strike to protest against the lockdown.

At one bus stop, a truck owned by city government pulled up to let passengers board.

One company said it decided not to dispatch its buses. Its representative told a reporter it would be costly because of restrictions on how many passengers each bus could take.

The government has instructed buses and jeepneys not to load up on passengers and keep a seat vacant between them, if possible, as to enforce social-distancing measures to check viral spread.

But that experiment seems to be failing.

Jeepneys were seen still loaded with passengers.

At one road in Manila, an enforcer was flagging jeepneys and asking some passengers to alight in order to allow those remaining inside to sit further apart.He stopped as many jeepneys as he could, but most just slipped right through.

Inside MRT stations, security guards managed to put distance between queueing passengers. But the trains remained packed.