Officially, China does not back Russia militarily, preferring to maintain a certain degree of neutrality on this matter. Nonetheless, logistics equipment manufactured by them was noticed on Rostov railway platforms.
Video evidence
A video captured the movement of equipment-laden railway cars at the Rostov station. The film opens with the 44 NJ2040 multi-purpose vehicle, a licensed Iveco VM 90 produced in China by the NAVECO consortium [a joint venture between China's Nanjing Motor Group Company and Italy's Fiat and Iveco]. This vehicle entered service with the Chinese National Liberation Army in 1999 and has since been utilized extensively in various configurations, including infantry transport, ammunition transport, and the HJ-9 anti-tank guided missile launch platform.
Next, two Shacman Shaanxi SX2300 88 trucks are shown. These automobiles have curb weights of 13,000 kg and payload capacities of 17,000 kg. In comparison, the load capacity of the popular KamAZ-63501 is 15,000 kg. These automobiles also served as the basis for other customized variants. Two tankers, a truck with a service body, and many different truck combinations, including a 66 [Shaanxi SX2190], are visible at the finish. China is secretly supporting the Russians, albeit not with lethal weapons [maybe also, but we don't know] but with equipment that is equally essential to the army's operation.
Russian losses
The massive losses of trucks at the outset of the war were so debilitating that the Russians required additional vehicles, for instance, to assure a steady supply of ammunition to the front. In addition, the Shaanxi SX2300's ability to transport an additional 2 tons of ammunition over the same route will be pretty valuable. This increases the possibility of shell loss in the event of an ambush.
Chinese equipment at Rostov suggests a second shipment is en route, most likely by rail. China's participation in the war in Ukraine may be a test of military equipment under combat situations, but it may also be a justification for imposing international sanctions against China, which, given China's current domestic issues, may not be very advantageous for China.