The driver was in a coma at one point but regained consciousness when he was sent to Princess Margaret Hospital, while four of his passengers were listed as being in serious condition.

The coach was carrying 26 passengers - 11 men and 15 women - on their way home from work.

Five passengers - two men and three women - were not injured and left after medical examination on-site.

The 22 injured people, aged 20 to 70, were sent to Yan Chai Hospital, Princess Margaret Hospital and Caritas Medical Centre for treatment.

The 64-year-old driver, Lee, suffered from serious injuries.

Dash cam footage shows the coach mounting the road's concrete central dividers near the Buddhist Lam Bing Yim Memorial School at 5.47pm, bouncing into the air for a few seconds before landing on its left side.

The coach then lay across the road, with both the front and back windshields broken, blocking two lanes of traffic.

Some of the passengers climbed out of the coach through the broken windows by themselves and waited for rescue by the roadside, while other injured passengers were lying in the coach.

At least 10 ambulances were deployed to the scene and emergency personnel spread mats with different colors on the road to separate injured passengers according to different conditions.

Three passengers were seen being placed on the yellow mat, suggesting they were in a serious condition.

A passenger said the coach is a company shuttle bus, carrying them from Tsing Yi to Tsuen Wan and Prince Edward.

She said she was sitting on the fifth row on the right side of the coach with passengers wearing seat belts.

"I heard some 'ping pong' sounds first, but the coach kept going and then flipped on its side," she said, adding that the vehicle was not going very fast.

She also added that it was chaotic inside the coach after the accident.

It is understood the coach is an employee shuttle bus for The Hong Kong Shipyard Limited and carries workers from the company in Tsing Yi to the MTR stations in Tsuen Wan and Prince Edward.

The Transport Department announced at around 6.30pm yesterday that all lanes of Texaco Road flyover near Castle Peak Road in Tsuen Wan was closed. It urged motorists to use alternative routing.

"Citizens heading to areas in the vicinity of Tsuen Wan should please consider using other public transport services, such as the MTR. Traffic is congested now," the department said.

And KMB bus routes 32M, 42C and 68A and Long Win Bus routes A41, A41P, E41 and E42 were also diverted.