A row between China and Taiwan has flared up over air navigation, leading to the cancellation of 176 flights between the two.

Taiwan split from the mainland in 1949, but is regarded by Beijing as “an inseparable part” of the People’s Republic. However, the island functions as an independent state that calls itself the Republic of China,

Up to a decade ago, anyone travelling between the two had to fly via Hong Kong or a third country. Then direct flights were permitted, and they continue across the Taiwan Straits today.

But Taiwan has objected to the flight paths of special services laid on for the impending Spring Festival (Chinese New Year). A new route known as M503 is said by Taiwan to pass dangerously close to existing airports on the disputed Tiaoyutai Islands in the straits.

Taiwan’s president, Tsai Ing-wen, tweeted earlier this month: “Recent unilateral actions by #China – including M503 flight route & increased military exercises – are destabilizing & should be avoided.”

The official China Daily in Beijing said the flights, operated by China Eastern Airlines and Xiamen Airlines, “were obstructed by the Taiwan aviation authority”.

The airlines have offered full refunds to around 25,000 passengers already booked on the flights.

China Eastern Airlines, based in Shanghai, called on the Taiwan authorities to “normalise the development of the cross-Straits civil aviation sector as soon as possible”.

Tension between mainland China and Taiwan is running high. Earlier this month the global hotel chain Marriott issued a profuse apology to the Chinese authorities after describing Taiwan, as well as Tibet, Hong Kong and Macau, as a separate country – a move interpreted by some as “disrespecting the sovereignty” of the People’s Republic.

Not long after, the Civil Aviation Administration of China (CAAC) demanded an “immediate and public” apology from Delta Air Lines for listing Tibet and Taiwan as countries on its website.