Kim Jong-un has travelled to China over a newly opened bridge marking the North Korean leader’s first known trip abroad in more than a year.

A South Korean government source told the Yonhap news agency that Kim had arrived in the Chinese border city of Dandong, in Liaoning province, after taking a train from Pyongyang to Sinuiju and crossing the New Yalu River Bridge.

Yonhap also reported that the Chinese premier, Li Qiang, had travelled to the city. Kim’s trip was not announced in advance and had not been confirmed by Pyongyang or Beijing by Saturday evening.

China will mark the anniversary on Sunday of its entry into the 1950-53 Korean war on the North’s side.

Japan’s Kyodo news agency said on Saturday that traffic controls had been imposed around the bridge and near a museum devoted to China’s role in the war, and that hotel bookings nearby had been restricted.

Diplomatic sources told the agency the measures were linked to a visit by a senior North Korean official.

The 3km bridge opened in…