A cargo ship rammed into a bridge in the Chinese city of Guangzhou early on Thursday, plunging five vehicles including a public bus into the river.
The accident killed two people and injured one. Three are still missing, state media said.
Images on broadcaster CCTV show a section of the bridge fractured, with the ship trapped under it. The vessel did not appear to be carrying cargo.
The incident happened at 05:30 local time (21:30 GMT).
The ship's captain has been detained and people residing in the vicinity have been evacuated, according to local media, citing district authorities.
The company that owns the ship said it is cooperating with the investigation, according to reports.
One report quoted a resident saying water supply and internet service in his neighbourhood were suspended.
In October 2021, provincial authorities had identified the need to reinforce the bridge, including constructing "collision avoidance facilities" at four bridge piers, CCTV reported.
The deadline for these works to be completed was postponed three times, most recently to August this year, according to the report.
Guangzhou lies on the Pearl River delta and one is of the busiest seaports in mainland China.
Nansha, the district where the incident took place, is the fastest-growing port in southern China, with cargo volumes increasing every year since it opened in 2004.
