The Philippines on Friday tightened testing protocols for foreign travelers to ensure the detection of new coronavirus strains.

Passengers from countries where new COVID-19 variants have been detected must undergo a second coronavirus swab test on their fifth day of quarantine, according to an order issued by an inter-agency task force.

Co-passengers and the partner of a 29-year-old Filipino infected with a strain first detected in Britain had tested negative upon arrival in Manila from the United Arab Emirateson Jan. 7, but later tested positive. The man left the Philippines for the UAE on Dec. 27.

The man had recovered from the new virus strain and was now negative, the Quezon City local government said on Friday.

“The doctors at the quarantine facility where he is staying will make a final assessment before he is allowed to reunite with his family and reintegrate with the community,” it said in a statement. “He will remain under health monitoring for at least two weeks.”

People who get negative results in both tests may go to their local destinations, which will monitor them for the rest of their two-week quarantine, according to the task force order. A new round of COVID-19 testing must be done before they are allowed to go home.

The task force allowed foreigners with valid visas, including personnel of accredited international organizations, and the spouses and minor children of Filipino citizens, to visit the Philippines as long as they get tested upon arrival at the airports. They must also promise to get quarantined for 14 days.

The Philippines on Jan. 15 extended the travel ban on more than 30 countries with confirmed cases of the more contagious COVID-19 variant until the end of the month.

Included in the ban are the UK, Denmark, Ireland, Japan, Australia, Israel, the Netherlands, China, Hong Kong, Switzerland, France, Germany, Iceland, Italy, Lebanon, Singapore, Sweden, South Korea, South Africa, Canada, Spain, the United States, Portugal, India, Finland, Norway, Jordan, Brazil, Austria, Pakistan, Jamaica, Luxembourg, Oman, United Arab Emirates, and Hungary.

Meanwhile, the Department of Health (DoH) on Friday said it would tap the National Bureau of Investigation (NBI) in locating two co-passengers of a Filipino who tested positive for a more contagious coronavirus strain.

Health Undersecretary Maria Rosario S. Vergeire said the contact number given by one passenger was an overseas number, while the other could not be reached. Their addresses were also incomplete.

“We’ve been trying hard to find them and we’re doing everything we can,” she told an online news briefing in Filipino.

“We’ve coordinated with the Department of Justice and we will be providing these two names to the NBI through the Department of Justice today,” she added.

More than a dozen close contacts of the passenger have also tested positive for the coronavirus. Health authorities have yet to find out whether they also got infected with the new variant.