Three people were killed and eight others were injured as three vehicles piled up on the Lucknow-Agra Expressway early Monday morning due to dense fog, police said.
The accident occurred in Erva Katra police station area in which a truck, a sleeper bus and a car crashed into each other, police said.
A joint rescue operation from police teams of different areas is underway, they said. The injured have been sent to Saifai Medical College, police said, adding efforts were on to identify the deceased.
Dense fog predicted over northern plains
Satellite images on Monday showed a thick layer of fog extending from Punjab to east Uttar Pradesh across Haryana and Delhi, the India Meteorological Department said.
The Met office reported visibility levels of 25 to 50 metres in Amritsar, Patiala, Bareilly, Lucknow and Bahraich early morning. The IMD has predicted dense to very dense fog over the plains in northwest India during the next five days.
According to the IMD, very dense fog is when visibility is between 0 and 50 metres, 51 and 200 is dense, 201 and 500 moderate, and 501 and 1,000 shallow.
Rail and road traffic in Delhi and NCR was affected due to a thick blanket of dense fog enveloping the region. Around 20 trains were delayed by 15 minute to 2 hours on Monday morning.
(With inputs from PTI)
