TV watchdog Ofcom has criticised Channel 4 for showing scenes of "violence, aggression and menace" when children were watching by broadcasting X-Men film Wolverine before the watershed.
The movie, the fourth in the fantasy franchise, was broadcast at 6.55pm on a Sunday evening.
Scenes included Wolverine (Hugh Jackman) as a young boy stabbing and killing a man who is subsequently revealed to be his father, and an intense surgery sequence in which Wolverine's head and body are drilled with holes and liquid metal is injected into him.
Channel 4 said it had "carefully edited" the 2009 film, which is based on the X-Men comics, to reduce the level of violence.
It said that the film franchise was "well-known for its fantasy, comic book style" and that the violence in the film is "not realistic in the context of normal everyday life".
But Ofcom said that the movie, X-Men Origins: Wolverine, "contained dark fantasy and violent themes throughout and a number of scenes of violence, aggression and menace".
It said that the edits were "insufficient to address the ongoing violent themes throughout the film".
The regulator said that 115,000 children, aged between four and 15, would have watched the film on Channel 4, and 46,000 of those would have been aged between four and nine.
It said that parents would not have expected "this level of intensity and violence to be shown on Channel 4" at that time on a Sunday evening and concluded that "children were not in this case protected from unsuitable material by appropriate scheduling".