A lorry ploughed through a Christmas market in Berlin, killing at least nine and injuring 50, in what police said was probably a deliberate attack.

A suspect was arrested, police said. They are thought to be the driver. The co-driver "died on the spot", police added.

Citing police at the scene, German media said first indications pointed to an attack on the market, situated at the foot of the ruined Kaiser Wilhelm memorial church, which was kept as a bombed-out ruin after World War Two.

Eyewitnesses reported that the lorry entered the market "at some speed - perhaps as high as 40mph", knocking down stalls before eventually coming to a standstill.

Video showed destroyed hoardings and stalls.

Mike Fox, a tourist from Birmingham, said that the lorry missed him by only about three meters as it drove into the market, tearing through tables and wooden stands.

"It was definitely deliberate," he said, adding that he helped people who appeared to have broken limbs, and that others were trapped under Christmas stands.

Another, Emma Rushton agreed that "it wasn't an accident."

She told Sky News: "It was going at 40mph through the middle of the market. There was no way it could have come off the road and it showed no signs of slowing down."

She added: "There were lots and lots of people, this is Monday evening, people had finished work. There were tourists there."

Jan Hollitzer, deputy editor in chief of the Berliner Morgenpost said: "I heard a big noise and then I moved on the Christmas market and saw much chaos...many injured people," "It was really traumatic."

A photo posted by his newspaper showed damaged tables and stalls.

Berlin Christmas market lorry attack Show all 18 1 /18 Berlin Christmas market lorry attack Berlin Christmas market lorry attack Several people have been killed after a lorry drove into crowds at a Christmas market in Berlin REUTERS/Fabrizio Bensch Berlin Christmas market lorry attack 'At least nine' people have been killed and more than 50 injured. AP Berlin Christmas market lorry attack Emergency Services rush a Berlin market victim to an ambulance Associated Press Berlin Christmas market lorry attack Police cordoned off the square at Kaiser Wilhelm Memorial Church following the incident REUTERS Berlin Christmas market lorry attack Rescue workers inspect the lorry that crashed into a Christmas market close to the Kaiser Wilhelm memorial church in Berlin EPA Berlin Christmas market lorry attack Emergency crews inspect the lorry that ploughed into a Berlin Christmas market, killing at least nine people AFP Berlin Christmas market lorry attack Fire crews attend the scene of the attack AFP/Getty Berlin Christmas market lorry attack Armed police secure the site of a lorry attack at a Christmas market in Berlin REUTERS Berlin Christmas market lorry attack Crushed debris is visible beneath the wheels of the vehicle REUTERS Berlin Christmas market lorry attack An injured man is pushed to an ambulance REUTERS Berlin Christmas market lorry attack Medics attend an injured person after the lorry attack which killed at least nine and injured more than 50 people AFP/Getty Berlin Christmas market lorry attack Firefighters examine the lorry which was rammed into a Berlin Christmas market REUTERS Berlin Christmas market lorry attack A person is carried into an ambulance REUTERS Berlin Christmas market lorry attack View of the lorry that crashed into a Christmas market in Berlin, killing at least nine and injuring at least 50 people AFP/Getty Berlin Christmas market lorry attack Rescue workers push a person on a stretcher to an ambulance Getty Berlin Christmas market lorry attack Firefighters assess the damage after the lorry rammed the Christmas market, killing 'at least nine', and injuring more than 50 people AP Berlin Christmas market lorry attack Firefighters stand beside a toppled Christmas tree at the site of the suspected terrorist attack in a Berlin Christmas market AP Berlin Christmas market lorry attack Damaged stalls at the scene of the incident at a Berlin Christmas market where at least nine people have been killed EPA

Police cars and ambulances converged quickly on the scene as a huge security operation unfolded. The fate of the driver of the truck was not immediately clear, but Bild newspaper said he was on the run.