Four people were injured - two seriously - when a van hit a group of people queuing to use a food bank.
Police said the crash involving "a number of people" happened at Kirk Hallam Community Centre in Derbyshire at 09:00 BST.
Three people were taken to Queen's Medical Centre in Nottingham and one person to hospital in Ilkeston.
A 37-year-old man has been arrested on suspicion of assault occasioning grievous bodily harm with intent.
Melissa Gamble, who was in the queue, said: "I don't know whether I got pushed by people or hit by the van, I'm not really sure.
"A friend was in front of me, she was bleeding from her ear. I was on the floor still, I felt a bit breathless. I'm still shook up, still shaky."
Another eyewitness Michelle Biggs, from Ilkeston, said: "It was horrendous, it all happened so fast.
"I just saw the white van speeding up the hill and I ran to my three-year-old, who was playing, and grabbed him."
On its Facebook page, the community centre said people were queuing to use a food bank at the time of the crash.
Det Sgt Scott Riley said: "There could be numerous reasons for this, and we ask anybody in the local area if they've got information for us."
Officers confirmed the crash was not being treated as terrorism.