MANILA - The Philippine civil service is facing paralysis, with top officials going on self-quarantine and key government offices shutting their doors as more cases of the coronavirus surface and unease over an undetected community spread continues to percolate.

On Thursday (March 12), the Senate as well as the Finance and Education ministries, the central bank, economic planning and telecommunication agencies, and parts of a compound where President Rodrigo Duterte holds office were either on lockdown or "restricted access".

The Asian Development Bank (ADB) and a government bank, both in Manila, also closed their headquarters.

All had announced that they were disinfecting their premises after learning they had visitors who tested positive for the virus or had come in contact with those infected.

Meanwhile, six Cabinet ministers, nine senators, the central bank governor, three big-city mayors and a congressman are now under self-quarantine.

Mr Duterte's daughter, Davao Mayor Sarah Duterte-Carpio, is herself in quarantine.

The President was having himself tested for Covid-19, the disease caused by the virus, and was considering self-quarantine, his spokesman, Mr Salvador Panelo, said.

Mr Duterte was at a road inauguration event on March 5 where he met with Transportation Secretary Arthur Tugade, who had by then already come in contact with a virus carrier at another event.

The finance and public works secretaries, the central bank governor and Mr Duterte's chief of staff were also there. They are now all on self-quarantine.

"I don't know the circumstances surrounding that," Mr Panelo said in a radio interview.

Mr Panelo said Mr Duterte did not exhibit signs of an infection, but had "opted to undergo the test to perform (his) duties as a government worker".

"This is a pre-emptive step to be sure that he's fit and healthy," he said.

He said Mr Duterte would fly to his home city of Davao on Thursday, where he would likely stay should he opt for self-quarantine.

A congressional hearing, meanwhile, seems to have set off the flurry of self-quarantine and lockdowns at the Senate and ADB.

A 72-year-old academic - an expert witness on education reform - who tested positive for the virus was at the hearing.

Only two senators were at the hearing, but seven other senators had opted to quarantine themselves.

Ms Duterte-Carpio, the Education Secretary and a congressman were at the hearing.

"This virus is no joke... Many think we are panicking but if you love your parents, grandparents, you should take this virus very seriously," said Senator Miguel Zubiri.

Senator Panfilo Lacson said: "Better safe than sorry."

The academic was also said to be present at an event at the ADB, which prompted the bank to shut its headquarters in Manila and put its staff on work-from-home arrangements.

"The safety of staff, visitors to the bank, and their families is of utmost importance to us," ADB official Deborah Stokes said in a statement. "We are providing support to the staff who interacted with the visitor."

The ADB has more than 2,600 full-time staff in Manila.

The Philippines so far has 49 confirmed cases of infection, with the spike in number happening in just the past six days.

There are close to 100 Filipinos who have also tested positive abroad, including six who are in Singapore.

Mr Duterte has declared a health emergency, and the Philippines is currently under "code red sub level 1", the second highest.

Officials are now weighing whether to raise the alert level to its highest as more confirmed cases are being reported, suggesting "sustained community transmission".

Posts on social media show that the slow announcement of officials putting themselves on quarantine and government offices shutting down, as well as persistent rumours of community-wide lockdowns, have been setting off panic buying across Manila.