Pyongyang could very well be helping Moscow to gear up in its war with Ukraine, according to satellite imagery of the Tumangang rail facility at the border with Russia recorded by the U.S. think tank Beyond Parallel and made public on Friday.

Although “the extensive use of tarps” makes it impossible to confirm whether this is actually artillery being transferred, the “unprecedented number of freight railcars” and level of rail traffic, along with the recent discussions between the two countries, seem to suggest so, the organization said.

The traffic has recently been “far greater” than what has been observed in the past five years, including pre-COVID-19 levels, when there would be 20 railcars at the facility at most, it added.

Last month, North Korean leader Kim Jong-un pledged his full support to Russian President Vladimir Putin and his “sacred fight” at a summit where both men discussed possibilities for military cooperation.

Five days after the high-level meeting, satellite imagery showed a “gradual but steady increase” of freight boxcars, culminating to the “unprecedented” numbers of 73 railcars on October 5, according to Beyond Parallel.