At least 10 people were injured in Taiwan's northeastern country of Yilan on Tuesday after a bridge collapsed as a tanker truck was crossing it, media reported.
"As of 1:00 pm (0500 GMT), 10 people and two coastguard personnel were injured and there could be six more people who are still trapped in fishing boats. The rescue operation is ongoing," the Taiwan Central Information Agency said in a statement.
The cause of the collapse is being investigated.
"Saving life is priority," Taiwan Premier Su Tseng-chang said in a Facebook post. "I will ask related authorities to make all effort for the rescue."
The steel bridge, which is 140 metres long and 15 metres wide, was built in the late 1990s in the fishing port of Nanfangao.
The Nanfangao Viaduct was the first bifurcated single-arch bridge in Asia.