Rail traffic along the North Korea-Russia border spiked this week to its highest level in years, suggesting arms supply by Pyongyang to Moscow after their leaders discussed deeper military cooperation, a U.S. think tank said on October 6. Satellite imagery showed an "unprecedented" 73 or so freight cars at Tumangang Rail Station in the North Korean border city of Rason, the Beyond Parallel Project of the Washington-based Center for Strategic and International Studies said in a report.