Rescuers check the scene on Nov 16. [Photo/Xinhua]

LANZHOU - The death toll in a school bus accident that occurred on Wednesday morning in the northwest province of Gansu has risen to 20 following the death of one child later Wednesday.

The victims, including 18 preschoolers and two adults, died in a head-on collision between a school bus and a truck in the city of Qingyang, said an official from the city's work safety bureau.

The accident happened around 9:40 am in Yulinzi township of Zhengning county, according to a statement from the bureau. The statement said five people died at the scene, including four children and their bus driver, while 15 others, their teacher included, were confirmed dead by the afternoon.

The statement said another 44 children were injured in the accident and have been hospitalized. Twelve of the injured are in a serious condition.

The truck had a license plate from the neighboring province of Shaanxi and was carrying coal, the statement said.

The bureau has blamed overloading for the accident, stating that the bus -- a van with nine seats -- was carrying 64 people, most of whom were children from Yulinzi's Little Doctor Kindergarten, a privately-run kindergarten located in the rural area.

According to the statement, it was foggy when the accident occurred and the van was in poor condition. The truck driver has been taken into police custody.

The accident is one of many in China involving school buses or students.

On October 28, 19 people, including 10 children, were injured when a school bus from a kindergarten hit a van in the northwest Xinjiang Uygur autonomous region.