Five persons, including four of a family, were killed and 15 injured on Wednesday when 25 vehicles collided with each other on Delhi-Ambala National Highway-1 in Karnal district.

A car collided with a stationary truck in Nilokheri in Karnal on Wednesday morning owing to reduced visibility due to dense fog, following which other vehicles which were close behind rammed each other, Karnal SP, Pankaj Nain said.

"Five persons were killed in the mishap," he said, adding, among the dead, four were members of a family from Uttar Pradesh, who were going to Punjab to attend a wedding.

The seriously injured have been admitted to a nearby hospital, police said.

The highway has been cleared and normal movement of traffic has been restored, they added