The Philippines on Monday accused China's coast guard of trying to block one of its vessels supporting a resupply mission for troops stationed on an atoll in the disputed South China Sea by directing a "military-grade laser" at crew on the ship.
In a statement, the Philippine coast guard said the Feb 6 incident took place at the Second Thomas Shoal, when a Chinese coast guard vessel directed the laser at its ship, causing temporary blindness to crew on the bridge and making "dangerous manoeuvres".
"The deliberate blocking of the Philippine government ships to deliver food and supplies to our military personnel... is a blatant disregard for, and a clear violation of, Philippine sovereign rights in this part of the West Philippine Sea," the statement said.
The Chinese embassy in Manila did not immediately respond to a request for comment. China has said it was ready to manage maritime issues "cordially" with the Philippines during President Ferdinand Marcos' visit to Beijing in January.
Known locally as Ayungin, the Second Thomas Shoal, 105 nautical miles (195km) off the Philippine province of Palawan, is the temporary home of a small contingent of military aboard a rusty ship.
The 100-metre long (330-ft) World War Two ship was intentionally grounded at the shoal in 1999 to reinforce Manila's sovereignty claims in the Spratly archipelago.
China's reported blocking of a resupply mission comes as Marcos has expressed openness to forging a Visiting Forces Agreement (VFA) with Japan to boost maritime security.
In August, Chinese coast guard vessels, with Chinese maritime militia, blocked Philippine coast guard ships providing security to navy resupply boats, the coast guard statement said.
Marcos was last week on a five-day visit to Japan to forge closer security ties with Tokyo, which in December announced its biggest military-build up since World War Two, fuelled by concerns about aggressive Chinese actions in the region.
The president's first visit to Japan since taking office came after he recently granted the US access to additional military bases in the Philippines under a VFA, a move that China said undermined regional stability and raised tensions. The VFA provides rules for the rotation of thousands of US troops in and out of the Philippines for exercises.