COACH passengers say they were left terrified after their driver apparently 'fell to sleep' at the wheel. 

The incident happened on the M3 near Winchester on Thursday, September 29 onboard the National Express service that was travelling from Gatwick airport to Bournemouth.

Speaking to the Mirror, marketing specialist Omar Reyes, 26, said a passenger shouted to the driver that he had missed his stop.

He said: “There was no answer, the bus started moving to the left side and collided with barriers.

READ MORE: Albanian crime group that smuggled migrants through two Hampshire ports is dismantled

"I screamed to the driver ‘stop the bus, man!’ then he kind of woke up and veered to the right and then back to the left side, hitting road signs.

“The driver then stopped the bus and we were all going crazy. We were all in shock.”

A spokeswoman for National Express said they would be conducting an internal investigation.

She said: "There was an incident with the Gatwick to Bournemouth service while travelling southbound on the M3 on Thursday, September 29.

"The police did attend the scene but there has been no further involvement. No injuries were reported and all passengers were provided with onward travel.

"We take any incident seriously and an internal investigation is underway to fully understand what happened. This will include reviewing information from our onboard systems and speaking with the driver, who we are fully supporting."

Hampshire Constabulary has been contacted for comment. 

SEE ALSO: Tensions arise over popular beauty spot as dog owners told to keep their pets on a leash