NYINGCHI, Tibet -- Four people went missing after part of a bridge deck in Tibet collapsed on Friday night, local authorities said Saturday.

The accident occurred at about 11:27 pm Friday on the Tongmai suspension bridge on the Sichuan-Tibet highway in Bomi county, disrupting traffic on the major road in the southwestern autonomous region, the county government officials said.

A truck with two local villagers aboard fell into the river and went missing. Meanwhile, another two hikers, a 24-year-old woman from Jiangsu Province and a 25-year-old man from Anhui Province, were also missing, the officials told Xinhua at the site.

Traffic police at the two sides of the bridge have blocked the traffic and were directing and dispersing vehicles and personnel.

It would take at least one month before the traffic could be resumed, local transport authorities said, asking vehicles to choose other roads during the period.

The bridge, 258 meters long and 31.5 meters high, only allowed one vehicle to pass at a time.

The transport authorities also advised that drivers and passengers guard against frequent occurrence of natural disasters on the Sichuan-Tibet road in the raining season.