SINGAPORE — The Philippines has sent fresh supplies to its decrepit outpost in the South China Sea, despite a Chinese blockade.

The mission to Second Thomas Shoal came as long-running tensions flared up after Manila's coast guard cut China's barriers in disputed waters.

The BBC witnessed how Chinese vessels manoeuvred against the Filipino ships, but two got through the blockade despite a near miss.

It was a ringside seat to a cat-and-mouse chase that has been escalating.

Manila resupplies its outpost in Second Thomas Shoal - a rundown navy ship with a handful of troops - every month to reinforce its economic rights to waters that are both rich in fish and mineral resources, and also strategically located south of Taiwan.

China claims almost the entire South China Sea and Taiwan, a self-governing island which it regards as a renegade province. Its claims to the sea overlap with those of the Philippines, Vietnam, Brunei, Malaysia and Taiwan.

In recent months, tensions have been especially high between China and the Philippines, which recently strengthened military ties with the US, Beijing's chief rival for influence in the region.

The Chinese coast guard condemned the latest resupply mission, saying the Filipinos entered what it calls the Nansha islands without its permission. The Philippines calls it Ayungin Shoal, after a small fish that is a local delicacy.

The three-day journey of two Philippine coast guard vessels and two tiny commercial boats to Second Thomas Shoal proceeded in rough seas due to an oncoming typhoon and the seasonal monsoon.

A little past dawn on Wednesday, the second day of the mission, the Filipinos were met by a white ship marked China Coast Guard, as well as two blue militia vessels with Chinese markings.

The Chinese ships were roughly five times larger than the two Filipino commercial boats that carried supplies that are good for roughly one month.

The two Philippine Coast Guard ships served as security escorts and the BBC was on board one of them.

The Chinese ships sent radio challenges to the Filipinos, asking them to leave.

When the Philippine ships refused, the Chinese ships aligned in a box shape to block them.

The two Filipino commercial ships got past the blockade because of their small size, a strategy that has worked in recent months.

But the two Philippine Coast Guard ships were too big to pass and at one point, got within a few metres of the Chinese ships. They were so close that their crews took photos of each other.

At one point, a Philippine military plane was also seen flying overhead.

The Philippine ships turned back at sundown when they confirmed that the supplies had been delivered and that the two commercial ships were safely on their way back to port.

All four vessels made it back to port, several hours drive north of the capital Manila, by Thursday, the third and last day of the mission.

Aside from sailing dangerously close to Filipino ships, China has been accused of firing water cannons and shining lasers on Philippine ships to drive them away.

Manila also claims that China deploys militia ships to boost its coast guard patrols in the disputed sea.

In 2016, an international arbitration court at The Hague ruled that China's vast sea claims had no basis, acting on a case brought forth by Manila. Beijing has refused to recognise it. — BBC