Seven people were killed and one more injured in a freeway accident in northwest China's Gansu Province Saturday night, local police confirmed Sunday.

A tractor trailer crashed into a sedan car and a motorcycle running in the opposite direction of the freeway near Yanjiaping tollgate inside Gansu, before knocking down a roadside high-voltage power pole and then falling off into a 5-meter-deep pit at about 10:40 p.m. Saturday.

The 93-km-long freeway links Lanzhou, the provincial capital, with Lintao County, which is located to the south of Lanzhou.

Altogether seven people were killed in the accident, including four from the car, two from the trailer and one on the motorcycle. One more on the motorcycle was also injured.

The injured was hospitalized.

Local traffic police are investigating the cause of the accident.