Central Asian states are facilitating a rail shipment of Chinese goods destined for Iran, according to Uzbek railway officials. The precise contents of the freight train are uncertain.

The block train, consisting of 55 container cars, crossed from China’s western Xinjiang Province into Kazakhstan on September 7, according to a report published by the Russian news agency Interfax, citing a statement by Uzbekistan’s freight rail operator.

The train will also pass through Uzbekistan and Turkmenistan before completing the 6,000-kilometre (3,728-mile) journey on or about September 21. The Uzbek statement notes that the shipment can confirm “the practical effectiveness of the China-Central Asia-Iran transport corridor,” establishing a work-around for Chinese-Iranian trade that circumvents seaborne shipments. Ship traffic in the Persian Gulf vicinity has been paralysed by the ongoing US-Iran conflict.

A block, or unit train, is a freight train that is uniform in its composition of wagons, and which moves directly from its origin to destination without making stops to pick up or offload cargo at points in between. In theory, block trains carry a single cargo, such as coal, cars or containers.

In the case of the China-Iran block train, the composition of the container cargo is not entirely clear, leaving open the possibility that it contains goods that Iran could use in its war effort against US forces. According to the Uzbek statement, “the train is carrying components for passenger cars, consumer goods, and other consolidated cargo."

China is currently engaging the United States in a comprehensive struggle for global influence. As part of that effort, Beijing is known to supply goods to Russia that help the Kremlin maintain its war effort in Ukraine. A US government commission has determined that “China has become the decisive external enabler of Russia’s war in Ukraine,” adding that “dual-use goods from China and Hong Kong keep Russia’s weapons programs running despite Western export controls.”

An investigative report published on September 10 by the Reuters news agency suggests China may be helping to prop up Iran in a way similar to its assistance to Russia. The report states that Chinese and Iranian officials have schemed to create a sanctions-busting barter system to facilitate Iranian oil exports in return for Chinese goods, including medicine, vehicles, military gear and air-defence equipment. The total value of the trade is estimated at $2bn-$2.5bn.

Iran, meanwhile, was a key supplier to Russia of drone technology during the early years of the Russia-Ukraine war. Now, apparently, the Kremlin is assisting Iran with rebuilding its drone capabilities via trans-Caspian Sea cargo shipments.

This article first appeared on Eurasianet here.