Manila, May 3 -- The Philippine National Police (PNP) vowed to pursue maximum legal action against individuals who physically attacked law enforcers during the Labor Day demonstrations in Manila on May 1.

PNP chief Gen. Jose Melencio Nartatez Jr. said investigators are gathering evidence, including from closed-circuit television (CCTV) footage, body camera recordings and videos on social media.

"We are preparing appropriate criminal charges now," he said in a news release.

Tensions briefly escalated during the Labor Day protest along Kalaw Avenue on Friday when a rallyist, who wore a face cover, punched an officer.

The PNP said seven police personnel were injured during the protests in Manila.

"Let me be clear: Peaceful assembly is a...