The Directorate General of Civil Aviation has said that fares on certain routes have gone up by 15 to 20 per cent in a month.
It has noted that there is no significant change in the cost of operations of airlines.
It has directed the airlines to ensure that there is no upward revision in tariff is effected due to ongoing industrial unrest in Air India and also surge in demand during this period.
Airlines have also been asked to see that the fare band published on Web sites is not be breached.