Dense fog over the city on Monday claimed a family of three, before disrupting flight and train schedules.

Tragedy struck the northern fringes of the city when Champa Sarkar, 30, her teenaged daughter Deepa and one-and-half-year-old son Jit were run over by a speeding train at a level crossing near Ashoknagar station.

In another fog-shrouded accident at Agarpara, also on the northern fringes, a 30-year-old unidentified youth was run over by a Sealdah-bound train.

Monday morning saw most flights being delayed by two-and-a-half to three hours, as poor visibility forced the Airports Authority of India to suspend operations.

The Met office said the wall of fog was caused by an anti-cyclonic circulation over west-central Bay of Bengal, near the Andhra Pradesh coast.

The Indian Airlines flight to Port Blair, scheduled to leave at 5.30 am, could only take off at 9.20 am, while the Calcutta-Delhi IC 263 flight departed at 9.35 am instead of 7 am. IC 676 to Mumbai took off at 9.40 am, instead of 6 am.

The Poorva Express, Doon Express, New Delhi-Howrah Rajdhani Express, Kalka Mail, Shipra Express, Mumbai-Howrah Mail via Allahabad, and the Asansol-Howrah Express arrived late at Howrah.

The New Delhi-Sealdah Rajdhani Express and the Darjeeling Mail reached Sealdah behind schedule.

The Howrah-Gorakhpur Poorvanchal Express and the Shipra Express were rescheduled on Monday for late arrival of corresponding Down trains due to fog, said officials.