Warning: This article contains details some readers may find distressing
The Metropolitan Police were tipped off on 3 May that two teenagers had allegedly dismembered the animals at Ickenham Road, Ruislip.
No arrests have been made.
Officers released footage of a boy and a girl on Thursday and asked people to help identify them.
The boy is described by the Met as 5ft 6in (168cm) tall, with short dark hair. He was wearing a dark jacket with long sleeves, with blue jeans.
Police sergeant Babs Rock said the boy “was also seen carrying a black duffel bag, which sadly is thought to have contained the kittens”.
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Sergeant Rock said the young girl was the same height as the boy, with long red hair.
“She was wearing a white top with black shorts. She was also carrying a purple jumper, which she later puts on to wear,” she said.
“If you know these two individuals then please come forward to us, we would like to speak with them as soon as possible.”
In the video, the pair are seen walking down a street and then later running back the way they came.
Sergeant Rock described it as “an incredibly distressing incident which I know has caused concern in the local community”.
