SINGAPORE - Three more weekly flights operated by Indonesia AirAsia to Singapore have been cancelled amid an official probe by the Indonesian authorities into the airline's flying permits.

With immediate effect, QZ367 from Bandung to Singapore will not fly on Tuesdays, Thursdays and Saturdays, The Straits Times has found out. It is not clear when or if the flights will resume.

This will bring the airline's number of weekly flights between Bandung and Singapore to 18, down from 21.

An airline spokesman confirmed the "temporary" suspension.

The latest development comes after Indonesia AirAsia was ordered to stop flying between Surabaya and Singapore for not having the necessary permits.

According to Indonesia's Transport Ministry, approval was given only for four flights a week on Mondays, Tuesdays, Thursdays and Saturdays.

But the airline was operating the route on Sundays as well, including on Dec 28 when the flight crashed into the Java Sea. There were 162 people on board the aircraft.

According to Singapore's civil aviation regulator, an airline must obtain approval from the authorities at both ends before it can operate a route.

When Indonesia AirAsia applied to the Singapore side for approval to operate the Surabaya-Singapore sector, the approval was granted based on available traffic rights under the air deal with Indonesia and landing slots at Changi Airport.

The crash of QZ8501 has triggered an extensive review by the Indonesian authorities into all flights operated by the airline.

"I won't be surprised if there are more suspensions in the coming days" an insider said.

The probe has also resulted in the suspension of seven officials over their suspected links to the unscheduled flight approvals.

The seven included two from the Transport Ministry, two from Surabaya's international airport operator PT Angkasa Pura I and three from state navigation operator AirNav Indonesia.