AirAsia Indonesia did not have a license to fly the Surabaya-to-Singapore route on Sunday that ended in tragedy, it has been revealed. The airline was approved to fly the route four days a week but it did not include Sunday. Indonesia's Ministry of Transport has announced a full investigation and suspended Indonesia AirAsia flights between the two cities. It will also check all other airlines operating in the country to make sure they were complying with license agreements. Indonesia AirAsia CEO Sunu Widyatmoko was quoted on local television as saying the airline would cooperate fully with the investigation and would not be releasing any statement until the results were known. He has not returned calls from CNN. AirAsia Indonesia is a subsidiary of the Malaysian-based AirAsia group. The parent company owns almost 49% of the Indonesian operation. The investigation will focus on the operations of AirAsia Indonesia and state-owned airport operator Angkasa Pura 1, which manages Surabaya airport. Transport Minister Ignatious Jonan described the airline's breach as a "serious violation." "How could they fly? Who would they have to approach to be able to make that flight. It would have to be the airport management or lobby air traffic control." He said the investigation is expected to take about a week. "It's not complicated. There is a checklist of what should and should not have been done."