Death toll has risen to seven in a mini-bus plunge accident in southwest China's Guangxi Zhuang Autonomous Region, after a child passenger died in hospital, local authorities said Wednesday.

An initial police investigation found that the 18-seat bus was loaded with 26 passengers including three children when the accident happened at 2:35 p.m. Tuesday in Liucheng County.

The bus glided backward after the driver stopped the bus to avoid a car on a slopping mountain road section. It rolled down a ravine of 54 meters deep.

Six passengers were killed and 13 others sustained injuries at the scene.