MANILA - The province of Zambales confirmed its first case of the coronavirus disease 2019 (COVID-19) on Thursday, joining a growing list of affected provinces and cities in the Philippines hit by the virus.

In a statement, the provincial health office said the first COVID-19 patient in Zambales is a 73-year-old US citizen living in Barangay San Gregorio in San Antonio town.

He reportedly had traveled from Cavite to Manila, one of virus-stricken cities in the Philippines, before returning to Zambales on March 15.

The following day, he developed fever and diarrhea, the provincial health office said. He later sought medical help at Our Lady of Lourdes International Medical Center in Olongapo City, but was referred to President Ramon Magsaysay Memorial Hospital due to unavailable resources.

He then underwent medical tests, before he was diagnosed with the virus.

"He is currently stable and was advised to continue strict observation and monitoring at home," said Dr. Noel Bueno, provincial health officer of Zambales.

It added contact tracing is ongoing and those who were exposed to him will also undergo medical tests.

"We are releasing this information for public awareness so proper precautions will be observed. We encourage everyone to strictly comply with social distancing, proper personal hygiene, cough etiquette and 'isolation'," Bueno said.

As of Thursday, the Philippines has recorded 707 cases of COVID-19, with 45 deaths and 28 recoveries, according to the Department of Health.