TOKYO (AFP) - A powerful typhoon was heading for Japan's southernmost Okinawa island chain on Monday (Oct 3), packing powerful winds that shut the airport and forced flight cancellations.

The "very strong" storm is set to hit the subtropical islands later in the day, packing gusts of up to 250kmh, Japan's weather agency said.

The storm was some 270km south of the Okinawan capital Naha early Monday, moving in a north-northeasterly direction, the Japan Meteorological Agency said.

After slamming into Okinawa, the storm is expected to hit Japan's main island of Honshu on Tuesday, said the agency, which has issued high wave and storm warnings.

The storm forced the closure of Okinawa's main Naha airport, the airport announced on its website. The airport said it would reopen on Tuesday.

Japan's two largest airlines, All Nippon Airways and Japan Airlines, said a combined 125 domestic flights had so far been cancelled due to the typhoon.

Classes at primary and secondary schools in Okinawa were cancelled on Monday, according to media reports.

Big storms regularly strike Japan, with 22 people killed when Typhoon Lionrock pounded the country last month, while another person was killed when Typhoon Malakas ripped across the country in September.