More than 20 people were left injured after a double-decker bus hit a bridge in Rochdale, ripping its roof off.
Eleven people were rushed to hospital, including one man in his 20s who suffered a broken jaw.
Pictures appear to show the roof of a number 17 bus detached and lying metres behind the vehicle, after it ploughed into a mainline railway bridge on Wednesday afternoon.
Police say 25 people were injured in total following the collision on Milkstone Road.
Ghulam Ahmad, who witnessed the incident, told the Manchester Evening News: "The top of the bus was gone. There were some people injured. One of them had an oxygen mask on. Some people were bleeding."
Two fire crews, a technical response unit and a major rescue unit were all sent to the scene to tend to injured passengers and investigate how the incident happened.
Greater Manchester Police's Inspector Stephen Clarke told journalists: “We are working closely with the emergency services to deal with all the passengers who have been involved in this incident and ensure they are all receiving the appropriate treatment.
“Clearly there are lots of people in shock but luckily no one was trapped on the bus."
“Our investigation into the cause of the collision is ongoing and we would encourage anyone with any information to get in touch," Inspector Clarke added.
Anyone with any information is encouraged to call police in Rochdale on 0161 856 8473.