KUNMING -- Four people died in a 53-vehicle pileup on a freeway in Southwest China's Yunnan province, police said.

The pileup occurred at around 6:10 am Monday in Kunming city, on the freeway that connects Kunming, the provincial capital, with Chuxiong, also in Yunnan. Four people died after falling off a highway bridge when trying to move to another lane, according to the provincial traffic police.

Three people suffered minor injuries in the pileup.

A preliminary investigation showed that icy roads were blamed for the pileup.

The freeway was temporarily closed to traffic, with more than 80 people stranded.