A BUS transporting workers has toppled over in Spain with shock pictures showing the vehicle flipped at the entrance of a tunnel.
Two people were badly injured in the smash and the driver remained trapped, according to early reports.
The bus flipped over at about 8:45am after a collision at the mouth of the tunnel.
The horror smash occurred on the C-32 highway in Barcelona between Pineda de Mar and Tordera.
Fire trucks, ambulances and medical helicopters rushed to the scene.
All passengers were pulled out from the wreckage but the driver remained trapped inside, according to TV network RTVE.
Reports on injury numbers range from 15 to 30 but two people are said to be in a a serious condition.
The bus was taking workers from Barcelona to Tordera.
Passengers were staff of Inditex, the Spanish multinational clothing company behind popular brand Zara.
As many as 60 were onboard heading to the the Inditex logistics centre in Tordera, La Vanguardia reported.
The newspaper said it spoke to a worker named Julieta, who was onboard the bus and injured in the crash.
She said shortly before being taken to hospital: “I fell asleep and I didn’t hear anything. Suddenly, we were all thrown out.”
Crash investigators are probing whether the bus had a tyre puncture, leading to an explosion sound that witnesses claim to have heard.
The bus could have then lost control, colliding into the side of the road and flipping upright at the tunnel’s entrance.
Traffic patrols were called to the scene to work with emergency services, police said.
The C-32 is now closed northbound.
Catalonia authorities have sent out a ‘PROCICTAT’ alert, only issued for special emergencies.
Pictures show the bus remaining upright, with a group of firefighters climbing up to the top of the tunnel to reach the front of the vehicle.
Inditex informed other staff members of the accident, saying there were injuries with workers taken to hospital, Spanish press have reported.
Catalonia minister Joan Ignasi Elena said: “Following with concern the accident of a bus on the C-32, between Pineda and Tordera, with dozens of people inside.”