BBC One drama Casualty has come under fire from TV regulator Ofcom, which said the opening episode of the show’s latest series breached the broadcasting code.

The edition, entitled One Extreme to Another – Part 1, followed the events at a coach station where a bomb exploded.

Four viewers complained at what was described as ‘graphic and repeated imagery’ of injuries sustained in the episode, which was transmitted in a pre-watershed time slot.

Those who complained to the BBC said ‘there was no specific warning’ about what was to come.

Among the graphic scenes, which aired just after 8.20pm, were an arm amputation, and a man whose stomach had been ripped out of his torso, revealing his intestines.

Ofcom ruled that the material was, in fact, unsuitable for children who may have been watching at the time, and therefore in breach of the broadcasting code.

The regulator stated: “While appreciating the experiences of the junior doctor (Toby De Silva, played by Matthew Needham) were integral to the storyline, Ofcom does not accept that the repeated images of injury were sufficiently brief and limited.”

In response to the complaints, the BBC said the ‘pre-transmission announcement and clear build up to the scenes would have sufficiently prepared viewers for such images’ and ‘the process of the arm amputation was explained to the junior doctor before it began, so giving the audience an opportunity to look away if they wished.’