A towering arched bridge over a bay in eastern Taiwan collapsed Tuesday, sending an oil tanker truck falling on to boats in the water below.

An air force helicopter, fishing vessels and more than 60 military personnel, including divers, were searching for possible victims.

Six people are believed to be trapped on one of the boats, the National Fire Agency said.

Taiwan Bridge Collapse
The 460ft long bridge collapsed in Nanfangao (AP)

Interior minister Hsu Kuo-yung said about five people were feared to have been on the bridge when it collapsed.

Ten people were sent to hospitals, six of them with serious injuries.

The 460ft-long bridge collapsed at about about 9.30am in Nanfangao, a tiny but often-crowded Pacific coast fishing village.

The weather at the time was sunny, hours after a typhoon swept across parts of the island.

Disaster relief officials would not say if the storm had weakened the bridge or give other details on the potential cause.

Taiwan Bridge Collapse
A disaster relief official said the collapse set off a fire and at least 10 people have been hurt (Taiwan’s Coast Guard/AP)

Government-run Central News Agency said a bridge pier may have collapsed.

Taiwan president Tsai Ing-wen said she hoped all government departments would do everything possible to save people and “keep the number of deaths and injuries as low as possible”, CNA reported.

National Fire Agency spokesman Su Hong-wei said the tanker’s fall smashed three boats.

Of the 10 people in hospital, six are Filipinos and three are Indonesians, the agency said in a statement. People from both countries regularly staff Taiwanese-registered boats.

Typhoon Mitag had brought high winds and heavy rain to northern Taiwan on Monday before moving northeast. Flights and ferry services had been cancelled Monday.

Nanfangao Bridge is a tourist attraction in Yilan. It was opened in 1998 and was built to replace a lower bridge that prevented large fishing vessels from passing underneath.

According to the company that designed the 60ft-high bridge, MAA Consultants, it is the only single-span arch bridge in Taiwan supported by cables and the second single arch-cable steel bridge in the world.