China on Wednesday landed two test flights on an island it has built in the South China Sea, four days after it angered Vietnam with a landing on the same runway in the disputed territory, the official Xinhua News Agency said.

The two flights are likely to spark further condemnation from Vietnam, which launched a formal diplomatic protest over the weekend, and the Philippines, which said it was planning to do the same.

Both countries have claims to the area that overlap with that of China, which claims almost the whole of the South China Sea.