File photo

Six people were killed when an ambulance carrying a dead body collided with a truck in eastern Nepal, police said Sunday.

The accident happened Saturday night near Haripur, a village about 353 kilometers (219 miles) from the capital, Kathmandu. A police officer said the crash may have been caused by speeding and a lack of visibility on the highway because of fog.

"The accident site is a few kilometers away from the river, and the highway usually gets foggy during the night in winter," said Hemanta Tamang, a duty officer in the area.

Tamang said the ambulance was carrying the body of an 85-year-old woman. "All the dead except the ambulance driver were her relatives," he said. 

Police said they were still searching for the truck driver, who is believed to have fled the accident scene following the crash.

Road accidents are common in Nepal and are often blamed on old vehicles, ill-maintained highways, poor road safety and drunk driving. At least 550 people have been killed in road accidents since mid-July, according to police.