The souring relationship between China and Australia is spiralling into a humanitarian crisis for seafarers, with more than 20 coal carriers reportedly stuck in North China.

Citing an analysis of IHS Markit, Global Ports and its own data, Bloomberg estimated a total of 21 bulkers in the Chinese port of Jingtang have faced prolonged delays.

Carrying roughly 400 seafarers and 2m tonnes of coal from Australia, those were composed of eight capesize and 13 panamax bulkers.