Rescuers search for trapped people at a collapsed factory building in Wenling, east China's Zhejiang Province, July 4, 2015. The accident occured at about 4 p.m. Saturday. [Photo: Xinhua]

The death toll from a shoe factory collapse in the city of Wenling, Zhejiang province, has risen to 11.

33 others remain hospitalized.

Mao Weihua, vice-director of one of the hospitals treating some of the injured, says many of the injured are suffering serious injuries.

"We have set up a special emergency team for these patients. The team consists of surgeons-in-charge and orthopedists-in-charge. We observe and discuss their condition everyday and find the most proper treatment. If we run across difficulties, we'll ask the doctors from bigger hospitals for help."

51 people were working inside the brick-built shoe factory in Wenling when it collapsed on them late Saturday afternoon.

Only 9 inside the building managed to make it out unscathed.

The last of the 42-others trapped under the rubble were pulled free early Sunday morning.

Around 300 people took part in the rescue operation.

Authorities have not said what they believe may have caused the building to come down.