A powerful typhoon packing winds of up to 270 kilometres (170 miles) per hour was churning towards Okinawa in southern Japan on Saturday, grounding nearly 80 flights, officials said.

Typhoon Sanba, located in the Pacific about 310 kilometres south of Okinawa at 0700 GMT, was forecast to make landfall early on Sunday, the Japan Meteorological Agency said.

It was expected to move over the East China Sea and reach a strait between the Korean peninsula and Japan's main island of Kyushu on Monday afternoon.

All Nippon Airways and Japan Airlines cancelled a total of 76 flights to and from Okinawa, affecting 17,000 passengers, airline officials said.

Nadine becomes hurricane: US forecasters
Miami (AFP) Sept 14, 2012 - Nadine strengthened to a hurricane Friday as it swirled in the Atlantic Ocean, though it posed no threat to land, US forecasters said.

With top winds of 75 miles (120 kilometers) per hour, Hurricane Nadine was a category one storm on the five-point Saffir-Simpson scale.

The US National Hurricane Center said the eye of the storm, the eighth hurricane of the 2012 Atlantic season, was centered about 725 miles east of Bermuda.

It was moving north-northeastward at 14 miles per hour.

"A turn toward the northeast and a slight decrease in forward speed are expected by Saturday morning, followed by an acceleration toward the east Saturday night and Sunday," the Miami-based NHC said in an advisory.

It said little change in strength was expected over the next 48 hours.