Airlines Tonga has collapsed leaving dozens of people stranded.

It is one of two airlines operating Tonga's domestic air services and says its flights are suspended indefinitely.

The collapse comes just days after coronation celebrations and one of the busiest times for Tonga's domestic air services.

The Matangi Tonga says a number of passengers, who had bookings with Airlines Tonga, remain stranded in Vava'u and Ha'apai, unable to connect with international flights.

Graham Jenkins from the kingdom's other domestic airline, Chathams Pacific, says they are putting on extra flights to help.

"We are comfortable we'll be able to pick up most of the passengers who remain stranded."

Tonga's civil aviation minister, Paul Karalus, is out of the country and is unavailable for comment.