India, Dec. 16 -- At least four people were killed and 25 others injured after a massive pile-up involving eight buses and three cars on the Delhi-Agra Expressway in Uttar Pradesh on Tuesday amid dense fog.

The accident occurred on the Agra-Noida carriageway of the Yamuna Expressway, Superintendent of Police Shlok Kumar told India Today.

Poor visibility due to heavy fog reportedly triggered the collision, leaving drivers with little time to react.

Several vehicles caught fire following the crash.

The injured were taken to hospitals in Mathura and nearby districts, with the condition of some reported to be critical.

An enquiry has been initiated to determine the exact sequence of events leading to the accident.

Expressing grief, Utta...