Several people were killed and others injured when a bus rammed into a bus stop queue in central Stockholm during Friday’s afternoon rush hour, police said.

Shortly after the crash, images in Swedish media showed a swarm of police, ambulances and emergency vehicles at the scene, with rescue crews crouched down along the underside of the double-decker bus, appearing to help people trapped underneath.

“There are both injured and deceased people in the incident. Police are for the moment not commenting on the number, gender or ages of the victims,” a police statement said.

Health authorities spokeswoman Michelle Marcher said that two seriously injured people had been transported to hospital.

Police spokeswoman Nadya Norton said the cause of the accident was still unknown.

“The investigation will have to determine what happened. It’s too early to say and I don’t want to speculate,” she said.