Beijing has taken aim at Vietnam and demanded fishermen be given an "education" on "illegal activities" in the South China Sea, as regional tensions ramp up. The demands were made in response to Hanoi's fury at China's detention of Vietnamese fishermen and fishing vessels in the disputed Paracel Islands.

AMTI flagged in June that the reef indeed had the potential to host a 3,000-meter runway like those that China has in the Spratlys. Vietnam currently has only one airstrip in the archipelago, on an island called Spratly, measuring 1,300 meters.

Vietnam's progress has been swift and quiet. In the past five months alone, it has reclaimed more than 2 sq km (0.8 square miles) in the contested Spratly Islands, according to Beijing-based think tank the Sea Probing Initiative.

The Philippine military has opened two weeks of combat drills that will include seizing an island in the disputed South China Sea and likely be frowned upon by China.

Hanoi is building runways, military structures on reclaimed islands at a ‘surprising’ pace, a think-tank said.

China has yet to respond to the call, which includes payment for two damaged boats and the return of rifles seized during the June 17 stand-off.