At least seven people were killed and nine others injured in a major road mishap in the northern Indian state of Haryana Sunday, a senior police official said.

"The mishap happened when the vehicle in which the victims were traveling collided head-on with a truck coming from the opposite direction near Dhakal village. Both the drivers of the vehicles failed to apprehend due to low visibility because of dense fog in the region," he said, on condition of anonymity.

While seven people, including two women, died on the spot, the injured have been admitted to a local hospital, the official said.

A probe has been ordered into the incident, he added.

Fog is common in northern India, particularly during the winter months of December and January, and is blamed for a number of road mishaps in the country.