Two men have been arrested after an officer was seriously injured by a van, Merseyside Police have said.
Officers said he was retrieving a backpack filled with cannabis that had been left in the road in the town of St Helens on Tuesday night.
As the officer fetched the bag on Hewitt Avenue at about 8.15pm, he approached a nearby white Ford Transit van whose occupants were acting suspiciously.
The van was then driven at the officer, striking him before being driven away, the force said.
The officer suffered serious injuries to his shoulder, right arm and right leg and was taken to hospital where his condition is described as stable.
A short time later it was reported two men were running from a vehicle into fields near East Lancashire Road and had discarded a bag.
The bag and the vehicle, which had been left on Ecclesfield Road, were recovered for forensic examination.
Two men from Rochdale were arrested on suspicion of causing grievous bodily harm with intent and are in custody for questioning.
Chief Inspector Jim Wilde said: "Every single day, Merseyside Police officers fearlessly put themselves in harm's way to protect the public from harm."
He added: "Sadly... our officer's dedication has come at a great cost to himself.
"Thankfully he is now receiving the care and treatment he needs, and everyone at Merseyside Police wishes him well. He will receive our full support as he recovers from this terrible incident."
He has urged anyone who may have witnessed any part of the incident, or who has CCTV or dashcam not yet submitted to police, to come forward.
You can pass on any information via DM @MerPolCC, Merseyside Police Contact Centre on Facebook quoting reference 22000339976, or alternatively call Crimestoppers anonymously on 0800 555 111.