Kittens thrown at moving train near Lingwood
Kittens were thrown at a train in what police described as a "horrendous" incident.
A train driver reported seeing a person throwing kittens from undergrowth on a foot-crossing close to Lingwood station, near Norwich.
British Transport Police (BTP) found a dead cat along with one dead kitten. Four other kittens recovered alive were treated for cuts.
The BTP has launched an appeal to track down the person responsible.
Sgt Alan Bowell said: "No animal should ever be subjected to such cruelty.
"Thankfully, not all the kittens were killed during this dreadful ordeal and are being well looked after."
The train was travelling between Norwich and Great Yarmouth.
BTP said it is believed the cat had died some time before the incident at 17:20 BST on 15 September.
The four surviving kittens were taken to Foxy Lodge Wildlife Rescue in Hemsby and two have since been rehomed.
An RSPCA spokesman said: "This sounds like a horrific incident for these poor kittens.
"Deliberate cruelty to animals is unacceptable."