The Philippines has reported its first cases of the highly contagious Delta variant in its sprawling capital, prompting calls from health officials to tighten quarantine curbs and border controls and ramp up a supplies-hobbled vaccine roll-out.

The Health Ministry said it found 16 infections caused by the Delta variant, first detected in India.

Five were Filipinos returning from overseas, while the rest were classified as "local cases", including two in Manila, home to some two million people. One of the two died as he was being rushed to hospital. The other managed to pull through. Most of the patients have not been inoculated.

Health officials insist there are no signs yet of a community transmission, as the cases appear "sporadic" and not found in clusters.

"If we look at the trend, it's sporadic. It's not clustered around a single place. It's just one case here, another there," Health Undersecretary Maria Rosario Vergeire told reporters on Friday.

But virus trackers are concerned the Delta variant may be fuelling a surge in densely populated cities south of Manila where infections remain high, although these places have been under lockdown for weeks. On Thursday, three cities in central and southern Philippines hit by a relentless wave of infections were placed under "enhanced community quarantine", the highest lockdown category.

The Philippines has so far managed to avoid a deadly outbreak of the Delta variant that has plagued its neighbours.

Indonesia has been setting records, with its daily caseload skyrocketing to over 50,000. Malaysia has also been tallying record cases, chalking up over 12,000 cases in recent days. Surges are also seen in Thailand, Vietnam and Myanmar.

The Philippines has kept its caseload at below 6,000 a day, though it still has the second-worst outbreak in South-east Asia, after Indonesia, with close to 1.5 million infections and over 26,000 deaths. The country reimposed curbs in Metro Manila and four nearby provinces after it went through a deadly surge in March and April that saw daily cases soaring to as high as 15,000.