A pair of buses were spotted crossing the border from North Korea into China three years and seven months after the North went into lockdown due to the COVID-19 pandemic.

Two buses that departed from the North Korean city of Sinuiju at around 10:15 a.m. Wednesday morning arrived in China's border city of Dandong about an hour later, crossing the Sino-Korean Friendship Bridge connecting the two regions.

While it remains unclear who was traveling on the buses, North Korean sources have reportedly suggested the vehicles could be related to the World Championships of the International Taekwon-Do Federation in Kazakhstan set for Saturday through August 26.

With Pyongyang reportedly planning to send over 100 athletes to the event, the team is likely to depart for Beijing via train later in the day and stay overnight at a dormitory run by the North Korean Embassy in China before boarding a plane to Kazakhstan.

Last January, the two countries' resumed freight train operations over the railway bridge, while partially restarting freight trucking between the two sides earlier this year.