A Chinese security vessel shone a "military-grade laser light" at a Philippine patrol boat in the disputed South China Sea, temporarily blinding crew members, the Philippine coastguard said Monday.
The incident happened on February 6 nearly 20 kilometres (12 miles) from Second Thomas Shoal in the Spratly Islands, where Philippine marines are stationed, the Philippine Coast Guard said in a statement.
There has been a series of maritime incidents between the Philippines and China, which claims sovereignty over almost the entire South China Sea and has ignored an international court ruling that its claims have no legal basis.
Days before this latest incident, the United States and the Philippines agreed to resume joint patrols in the sea, and struck a deal to give US troops access to another four military bases in the Southeast Asian country.
The Philippine coastguard patrol boat was supporting a "rotation and resupply mission" last week for the marines, who live in a derelict navy ship grounded on the shoal to assert Manila's territorial claims.
The Chinese coastguard vessel shone a "military-grade" green laser light twice at the Philippine ship, "causing temporary blindness to her crew at the bridge", the statement said.
The Chinese vessel also made "dangerous maneuvers" by coming within about 140 metres of the Philippine boat.
"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 Philippine Coast Guard said.
Manila refers to waters immediately to its west as the West Philippine Sea.
Despite the interference, the resupply and rotation of troops at Second Thomas Shoal were successful, Philippine Coast Guard spokesman Armando Balilo said.
Privately owned vessels are normally used to carry supplies, with the coastguard accompanying them.
Philippine military spokesman Medel Aguilar called on Beijing to "restrain its forces so that it does not commit any provocative act that will endanger the lives of people".
But Chinese foreign ministry spokesman Wang Wenbin said the Philippine boat had "intruded" into China's sovereign waters without permission.
He said the Chinese Coast Guard personnel had acted in a "professional and restrained" manner.
Chinese coastguard and maritime militia vessels also blockaded the Philippines-garrisoned shoal in August to stop government ships from reaching the troops, the Philippine Coast Guard said.
Philippine President Ferdinand Marcos and his Chinese counterpart Xi Jinping agreed in January to set up direct communication between their foreign ministries to avoid "miscommunication" in the area.
It is not known if the hotline was used in the latest incident.
The US-Philippine deal earlier this month brings to nine the total number of Philippine bases accessible to US forces.
It comes as the long-time allies seek to counter China's military rise in the region.
Vietnam, Malaysia and Brunei also have overlapping claims to parts of the South China Sea.