The crash on an Alton Towers ride that left 16 people injured, two with their leg amputated, has caused a significant drop in visitor numbers, the park's owner has said.

Merlin Entertainment, which owns Alton Towers, Chessington World of Adventure and Thorpe Park, said that revenues are down 11.4% since the start of the year.

Based on weaker trading in the summer and lower than normal bookings for the rest of the year, Merlin expects to report a profit towards the lower end of its £40-50 million estimate. Last year, it posted profits of nearly £90m.

Nick Varney, the chief executive of Merlin Entertainments, said: "The trends we reported at the half-year have continued throughout the summer.

"The performance of our Legoland Parks Operating Group has remained strong, with very positive guest satisfaction.

However, this has been offset by the impact of reduced visitation across the Resort Theme Parks Operating Group, primarily at Alton Towers resort, and euro weakness impacting visitation at our London attractions."

After crash, which occurred on the Smiler rollercoaster, 17-year old Leah Washington and 20-year old Vicky Balch both had a leg amputated. Leah's boyfriend, 18-year old Joe Pugh suffered severe knee injuries. And 27-year old Daniel Thorpe broke his lung and suffered a punctured lung.