Police are appealing for witnesses and information following a serious collision in Hemel Hempstead.
Officers were called at 8.18pm on Saturday to reports of a collision in Cherry Orchard involving a pedestrian and a white transit van.
The pedestrian, a man in his thirties, was taken to hospital where he remains in a serious condition.
Detective Inspector Adele Hopkin, who is investigating, said: “We are treating this incident as an attempted murder, involving people known to each another. I am urging any witnesses to come forward and report what you saw.
“The driver of the van, a male, did not stop at the scene so if you think you saw the van leaving the area, please get in touch. We’ve arrested a person in connection with this incident but we believe there is another male outstanding and we are carrying out enquiries to locate them.
“We would be grateful for any information. No matter how small it might seem, it could prove to be vital to our investigation.
“If you can help please get in touch on the non-emergency number 101 quoting crime reference 41/65961/19.”
You can also report information online at www.herts.police.uk/Report or speak to an operator in our Force Communications Room via our online web chat, which can be launched here: herts.police.uk/contact.
Alternatively, you can stay anonymous by contacting the independent charity Crimestoppers on 0800 555 111 or via their untraceable online form at www.crimestoppers-uk.org.
> A 23 year old man from Abbots Langley has been arrested on suspicion of attempted murder. He remains in police custody at this time.