Seoul, Jan 17 (IANS): A North Korean freight train crossed a border bridge into the Chinese city of Dandong on Monday, sources said, following another train's return to Pyongyang apparently with daily necessities and emergency relief items aboard.

The empty second train arrived in the Chinese border city earlier in the day, shortly after the first train departed the city at around 7 a.m. to return to the North's Sinuiju, Yonhap News Agency.

The first train had arrived in Dandong on Sunday, marking the first such train operation in one and a half years after the North shut down its borders to stave off the Covid-19 pandemic.

It was not immediately clear what the train carried home, but the sources said daily necessities, medical supplies and other emergency relief items seem to have been on board, with the train consisting of at least 15 cars.

The train services came ahead of such key events as the Lunar New Year, which falls on February 1 this year, the opening of the Beijing Winter Olympics on February 4 and the February 16 birth anniversary of Kim Jong-il, the late father of the current leader, Kim Jong-un.

South Korean sources said the North could continue shipping necessary materials from China via land routes starting with the latest train operation.