At least 14 people were killed when a decades-old lake barrier burst in Taiwan, authorities said on Wednesday, after Super Typhoon Ragasa pounded the island with torrential rains.

Ragasa lashed the northern Philippines and Taiwan on Monday with heavy rain and strong winds, forcing thousands to evacuate.

The barrier lake in eastern Hualien county burst on Tuesday, washing away a bridge and sweeping into a town.

"As of 7am Wednesday , 14 people are confirmed dead and 18 injured," Hualien County press officer Lee Kuan-ting said.

Lee told AFP rescuers were also searching for 30 people reported missing in the area.

Firefighting authorities later updated the number of missing people to 124.

Local authorities say flood water temporarily rose as high as the second floor of a house in some parts of the town on Tuesday, stranding about 263 people.

They were not in immediate danger and were asked to stay and wait for the water to recede.

Footage released by the local fire agency showed flooded streets and half-submerged cars as trees were uprooted in the area.

Across the island, more than 7,600 people were evacuated due to Typhoon Ragasa.

Around 3,100 people were evacuated beforehand and moved in with relatives in the area near the creek in Hualien, according to the fire agency.

Taiwan experiences frequent tropical storms from July to October.

Typhoon Danas, which hit the island in early July, killed two people and injured hundreds as the storm dumped more than 20 inches of rain across the south over a weekend. (AFP)