MUMBAI (Reuters) - A cold wave bringing dense fog this week to parts of northern India disrupted flights for a fourth straight day on Wednesday, delaying more than 100 and forcing cancellations of about 20.

Weather authorities forecast five more days of fog, with minimum temperatures on Tuesday ranging from 2 degrees Celsius to 5 C (35.6 degrees Farenheit to 41 F) in New Delhi, the capital, and the most populous state of Uttar Pradesh.

As many as 109 flights from Delhi's airport were delayed and 19 cancelled, aviation website Flightradar24 showed.

Low visibility resulting from the fog has caused widespread air traffic chaos this week, with hundreds of flights out of New Delhi delayed or cancelled.

(Reporting by Shilpa Jamkhandikar; Editing by Clarence Fernandez)