A North Korean cargo train pulled into a Chinese border town on Sunday, in what could be one of the first confirmed crossings since anti-coronavirus border lockdowns began, a source said, with South Korean media reporting that it was possibly picking up "emergency materials."
North Korea has not officially reported any COVID-19 cases and has imposed strict anti-virus measures, including border closures and domestic travel curbs since the pandemic began early 2020.
While Chinese data show some limited trade has continued, most shipments appear to be using North Korean seaports, not trains across its land borders.
Officials in Seoul said late last year they were watching closely for a resumption in cross-border rail traffic as a signal that restrictions might be loosening.
A North Korean freight train crossed the Yalu River railway bridge to arrive in the Chinese town of Dandong on Sunday, the South's Yonhap news agency said, citing multiple unnamed sources.
It was unclear whether the train was carrying any cargo into China, but was likely to return to North Korea on Monday with a load of "emergency materials," the sources told Yonhap, without elaborating.
Yonhap said it marks the first time that North Korea had formally opened its land border with China.
After nearly two years of border closures, some humanitarian aid is trickling into the country, though shipments of key supplies including food remain blocked, according to United Nations organizations.
Several shipments of nutrition and medical aid have entered the country after up to three months of quarantine at Nampo sea port, but there have been no confirmation of major shipments being transported by train.