An articulated truck caught fire inside the undersea tunnel of the Hong Kong–Zhuhai–Macau Bridge forcing the temporary closure of city-bound lanes and disrupting traffic on Tuesday evening.

The blaze was reported before 8pm in the tunnel tube of the 55km (34.17 miles) cross-border bridge. Video footage showed flames beneath the cargo truck and thick smoke filling the tunnel.

The city’s Transport Department announced soon after that all Hong Kong-bound lanes were closed, leaving only one lane available to motorists.

Images posted online showed cars at a standstill on the mainland section of the bridge.

Tuesday is one of the designated days under the “Northbound Travel for Hong Kong Vehicles” scheme, when motorists do not need to reserve slots to use the bridge, except on public holidays or the day before public holidays.

The scheme has drawn large numbers of Hongkongers to mainland China, particularly Zhuhai and Zhongshan, for leisure and entertainment.