Sixteen flights were diverted and four cancelled from the Delhi airport on Monday due to heavy fog, an official said.

Flights are operating at the airport under CAT III B conditions, which means the runway visual range (RVR) is between 50 metres and 175 metres.

Giving an update on flight operations at 11:08 am, the official said 16 flights have been diverted and four cancelled as of now.

"Owing to dense fog in north India our flights have been impacted across India. We will continue to review the situation and provide real time updates on our social platforms," said Indigo airlines in a statement.

The airline also requested passengers to check flight status before leaving home and reach out to its customer care.