TAIPEI (AFP) - Taiwanese were told on Wednesday (July 6) to brace for extreme winds and lashing rains as the first typhoon of the season bore down on the island.

Typhoon Nepartak was blowing gusts of up to 245kph, some 870km southeast of Taiwan's Hualien city at 0600 GMT (2pm Singapore time), the island's Central Weather Bureau said.

The "super-typhoon" would likely make landfall early Friday morning, the bureau said.

"As the typhoon kept gaining strength and approaching Taiwan over the past three hours, the Central Weather Bureau decided to issue a sea warning at 2:30pm," senior forecaster Chen Yi-liang told reporters.

"The typhoon could bring in strong winds and torrential rains...Residents must heighten their vigilance."

The tropical storm had a radius of 200km and was moving west-northwest at a speed of 22 kilometres an hour, the bureau added.

Super typhoon Dujuan killed three people and left more than 300 injured in Taiwan last year after it pounded the island with fierce winds and torrential rains that uprooted trees and triggered multiple landslides.