IndiGo cancelled more than 220 flights at Delhi and Mumbai airports on Sunday as disruptions stretched into a sixth day, even as efforts continued to restore normal operations.

The airline’s schedule chaos over the past few days has led to hundreds of cancellations and delays, affecting thousands of passengers. Sources said at least 112 flights were cancelled at Mumbai airport and 109 at Delhi.

On Friday, IndiGo cancelled about 1,600 of its 2,300 daily flights. Disruptions eased slightly on Saturday, with cancellations dropping to around 800, according to sources.

The airline said it operated 1,500 flights on Saturday.

Meanwhile, IndiGo's parent company InterGlobe Aviation announced that it has set up a crisis management group to monitor the situation. "Board of InterGlobe Aviation doing everything possible to ensure refunds for cancellations," IndiGo said in a statement.

IndiGo CEO Pieter Elbers and COO and Accountable Manager Porqueras on Saturday received DGCA notices, seeking explanations within 24 hours on the massive flight disruptions.

"The main objective (of operating just 700 flights on Friday) was to reboot the network, systems, and rosters so that we could start afresh today (Saturday) with higher number of flights, improved stability, and there are some early signs of improvement," IndiGo had said in a statement.