The trains collided in snowy conditions during the morning rush hour
At least 18 people have been killed after two passenger trains collided head-on at Halle, south west of Brussels.
Sebastien Duckers, 23, was a passenger on one of the trains travelling towards the Belgian capital. Here, he describes the accident.
I had just boarded the train two stops beforehand at Braine-Le-Comte on my way to work in Brussels, as I do every morning. Suddenly there was a loud bang and I was thrown forward and hit my head on the seat in front of me.
Thankfully I was not hurt and stood up immediately to see people thrown around the carriage.
Everyone was frightened and there was a lot of crying and screaming.
We were all in a state of shock.
There was broken glass scattered around the carriage.
Passenger Sebastien Duckers took this video after the accident
I walked around to see if there was anything I could do or if anyone needed my help, but nobody appeared to be hurt, just very shaken.
Thankfully we were three carriages back in the train, as the front carriages seemed to be the worst damaged.
I could see out the window that one of them was on its side. The train station staff and police were on the scene very, very quickly.
They shouted into the carriage, instructing us not to go out onto the tracks as there was a risk of electrocution after many live cables had fallen on the tracks.
After half an hour, we were led out of the carriage through the emergency exit.
One person was partially underneath one of the carriages and looked to be badly injured, but I could see their fingers moving
There was so much twisted metal, it was hard to tell what had happened and how much of our train had been damaged.
I just wanted to get away from the accident, and walked with the other passengers very silently up the tracks to the station, where a crisis centre was being set up.
I saw one of the front carriages completely destroyed and could also see some injured people being helped by emergency services by the side of the train.
One person was partially underneath one of the carriages and looked to be badly injured, but I could see their fingers moving. I could not tell if it was a man or a woman.
Once inside the crisis centre, we were separated into people who were injured and those who were not.
I could see some people with injuries lying around on stretchers being tended to by the emergency services, including one man who I could see had blood coming from his head.
But they did not seem to be the worst injured. They were still back on the train it seemed.
I asked my girlfriend to come pick me up and called work to tell them I was going back home.
After that I sat in shocked silence with the other passengers as we thought about how lucky we were that we were not in the front carriages.