A tourist who was enjoying Berlin's Christmas market with his girlfriend when a truck ploughed into the crowds has described the "carnage" at the scene.
Luke Theis, 21, and Lara Colombo, 22, both from Washington, US, were on the other side of Kaiser Wilhelm Memorial Church and heading to the area which was targeted when they became aware of the commotion.
Mr Theis, a student, told the Press Association: "We started seeing people running and hearing ambulances from all directions so we walked over. It was carnage everywhere. There was blood all over the floor.
"There were people lying on the floor - I am not sure what their condition was - I could count about eight lying down.
"The biggest mental image I have is there were two rivers of blood going down the floor.
"Nobody was really helping anybody. People were running. It was like every man for themselves. It was dusty and chaotic.
"There were ambulances and police sirens. People were yelling in German - I don't know what they said but it sounded like 'Get out, get out, get out'."
Concerned for his girlfriend's safety, Mr Theis decided to return to their hotel. But as they made their way back he said a fight broke out between some Germans and "Middle Eastern" men at the bus station.
The couple then got on a bus, where he said the driver targeted a woman wearing a burka who did not have a ticket.
He said: "When I got on the bus, the driver didn't ask for anyone's ticket but he was shouting 'Ticket, ticket, ticket' to a Muslim woman who had a stroller. No-one else was asked for their ticket. Another lady with a baby paid for her.
"You could feel the tension in the air - it was hostile. It seemed people were scared of people from the Middle East.
"There was this 'We don't want you here' vibe."
Mr Theis has booked flights out of Germany earlier than planned as the couple no longer feel safe, and they are leaving on Wednesday morning.
He said: "My girlfriend's safety is my priority. We are in shock. I think it hasn't settled. People have died right next to you. It won't settle for a couple of days.
"It's unsettling to think that you are so close to maybe dying. One minute you are alive and enjoying the Christmas market and then you are dead and your family has to spend Christmas without you.
"My heart completely goes out to all the victims' families."
Another witness, Jan Hollitzer, 36, said he heard screams as the truck made its way through the stalls, but that the market was "really silent" as "shocked" shoppers looked on at the aftermath.
Mr Hollitzer, deputy editor-in-chief of local news outlet Berliner Morgenpost, told the Press Association: "First, I heard a noise, then he destroyed the booths on the market and we heard some screams, and then the truck came out of the market on the left side."
Mr Hollitzer said he walked across the street to the market and saw destroyed stalls, broken glass, crockery and tables, and injured people lying on the ground.
"I moved forward and saw the back of the truck - it was a lorry," he said.
"There were some people under the truck and it was really scary, really terrifying.
"I moved on the street to see the front of the truck, which was destroyed."
Briton Emma Rushton, who was at the scene, said the market lights were torn down as the truck ploughed through.
She told the New York Times that the vehicle had "completely decimated" the hut in front of her, adding: "It happened so quickly that people wouldn't have had an opportunity to get out of the way.
"People were sitting, holding their heads. There were pools of blood on the floor. There were people in the recovery position.
"And it was completely decimated - the wood, glass, everything everywhere."
Mike Fox, from Birmingham, told the Associated Press that the truck had missed him by about three metres.
He said he had seen people trapped under stalls and others who appeared to have broken limbs.
"You do what you can to help who you can, really," he said.
"It happened so fast that there was nothing we could do to stop it - if we'd tried to stop it we would have been crushed."
Vivian Hilse, 15, a school pupil from Berlin, was at the market with her best friend when the lorry crashed into the market.
"I didn't see the lorry but I heard it, I heard people screaming," she said.
"We tried to run away but my best friend fell over and broke his leg.
"Everyone was running. I could hear screaming and saw lots of injured people.
"I was really afraid. We got in the ambulance and went straight to hospital.
"It was only when we were in the hospital that we knew what had happened.
"It is awful, you don't feel safe in your own city."
Berlin resident Andreas Heller, 56, was enjoying wine and a Bratwurst at the Christmas Market an hour before the attack.
"It was very festive and people were very happy - there was a lot going on," he said. "I live just three to five minutes away from here, I am shocked by what has happened.
"We were expecting something to happen but even so we are all deeply affected.
"These events are always exploited by the right wing populists to incite hatred. But that is what the terrorists want. What's very important is that people use their heads and think about what happened, to have a measured and intelligent response."
Mr Heller said Angela Merkel was being blamed by those affiliated to right wing parties, who described the victims as her dead.
"That is primitive and revolting," the retired carer said.