HONG KONG, July 30 -- At least 77 people were injured Tuesday after two double-decker buses collided just outside the Tai Lam Tunnel in Hong Kong, according to the Information Services Department of China's Hong Kong Special Administrative Region (HKSAR) government.

Around 8:30 a.m. local time on Tuesday, the Fire Services Department of the HKSAR government was informed about this accident, when the two buses collided outside the tunnel, which is a major road in the New Territories, leaving 77 people injured.

Most of the injured had been sent to different hospitals. Among the injured, aged from 16 to 67, five people were in serious condition, 54 kept stable, seven were discharged from hospitals, and others unknown, said a spokesperson for the Information Services Department of the HKSAR government.

Some passengers on one of the buses said that the speed of the bus was normal when the accident happened, according to local media.

Investigation into the cause of the accident is underway.