SINGAPORE - Two Singapore Airlines (SIA) flights have been rescheduled after a strong typhoon was forecast to hit Tokyo on Sunday (Sept 8).

In a travel advisory posted to its website, SIA said that the changes were due to Tropical Storm Faxai, which could blast coastal areas of Japan with winds up to 216kmh late on Sunday.

SQ630, which was scheduled to depart at 5.05pm on Sunday, has been re-timed to depart at 1.05am the next day. It is expected to reach Tokyo's Haneda Airport at 9am.

SQ639, which was scheduled to depart at 2.25am on Monday, will now do so at 10am and arrive at 4pm the same day.

All other SIA flights serving both Tokyo's Haneda and Narita airports are due to operate as scheduled, SIA added.

"As the situation remains uncertain, Singapore Airlines is monitoring the situation closely and customers may also check our website and social media platforms regularly for updates," Singapore's national carrier said in its statement in English and Japanese.

Japan's meteorological agency had earlier warned that "historic" winds and rain could cause landslides and flooding.

"Please be on full alert against gusts and high waves and be vigilant about landslides, floods and swollen rivers," the agency said in a statement.

The typhoon has already affected ferries and cancelled some 50 Shinkansen bullet trains to and from the country's capital city.

In its statement, updated at around 12.15pm on Sunday, SIA advised its customers to subscribe to its mobile notification service to receive updates on flight status, or to contact it if they need help.