Four friends returning from a wedding were killed when their car collided with an unknown vehicle on the Hisar-Chandigarh National Highway in Kaithal district, police said on Sunday.
The accident occurred on Saturday night near village Kyorak here, Investigating Officer, Rajbir, said.
The police officer said the four men, who were aged between 33 and 48, hailed from Mohali district of Punjab.
He said the four were friends and were returning home after attending a wedding in Jind.
A case has been registered against the unknown vehicle driver, he said.