Media playback is unsupported on your device Media caption The Chinese crew instructed the Filipinos to turn away

Journalists on board a Philippine ship have witnessed Chinese coast guard vessels trying to block access to a disputed shoal in the South China Sea.

One of the Chinese ships radioed to demand the crew turn around, or "take full responsibility" for their actions.

But the Philippine boat, ferrying food to troops stationed on the Second Thomas Shoal, managed to slip past.

The shoal is one of many flashpoints in the area, where several countries have overlapping territorial claims.

Multiple claims

China claims a U-shaped swathe of the sea - creating multiple overlaps with areas claimed by the Philippines, Vietnam, Brunei, Malaysia and Taiwan.

Saturday's incident, which took place at Second Thomas Shoal (known as Ayungin in Manila and Ren'ai Reef in Beijing), is a rare glimpse into the tensions that routinely play out in the disputed waters.

Image copyright AP Image caption The Chinese crew instructed the Filipinos to turn away

Image copyright Reuters Image caption Philippine crew members flashed peace signs at the Chinese vessel

Image copyright AP Image caption The Philippine boat slipped past the Chinese and reached their troops on a rusty beached vessel

Journalists say they saw two Chinese coast guard ships attempt to block the path of the Philippine boat, sending a radio message, in English, warning that it was entering Chinese territory: "We order you to stop immediately, stop all illegal activities and leave."

But instead of leaving, the Philippine boat managed to manoeuvre away and enter waters that were too shallow for the Chinese ships to follow.

The captain of the Philippine vessel, Ferdinand Gato, later told Reuters news agency that if they had not changed direction, they would have collided with one of the Chinese vessels.

Air-drop

Philippine troops are stationed on a beached, rusting military ship on the shoal that analysts say has become a symbol of the country marking its territory.

Two weeks ago, Manila made a formal complaint to Beijing after a similar incident when Chinese vessels succeeded in blocking a resupply mission to the shoal.

Image copyright Reuters Image caption These Philippine marines have been stationed aboard the BRP Sierra Madre for the last five months

Philippine planes resorted to air-dropping food and water supplies for the soldiers stationed on board the marooned ship.

The latest confrontation was witnessed by more than a dozen journalists.

They had been invited by the Philippine military to board the government vessel to show alleged bullying by Chinese vessels in the area.

The Chinese foreign ministry condemned the Philippines for trying to "hype up" the issue, according to a statement quoted by Xinhua news agency.

The ministry accused Manila of trying to "illegally seize" the shoal.

The incident comes a day before the Philippines is due to file a case against China with the UN tribunal in The Hague, challenging its territorial claim to most of the South China Sea.