Landbridge Group, the new operator of Darwin's commercial port, is among a number of firms in the key Chinese port city of Rizhao to have established armed militia units to support the military in event of war or major emergencies, according to an official military newspaper.

The reports in China's National Defence said the units, also known as "people's armed force departments", were trained to provide logistics, emergency rescue and combat readiness support. One report in November last year described the units, set up by 29 companies including Landbridge, as an important part of China's broader strategic goal to become a strong maritime power.

The Chinese port of Rizhao in Shandong province is also a major naval base. Credit:AP

The reports appear to contradict Landbridge's statements that material on its website had been "misconstrued" and depicted company security staff being trained in firefighting.