Manchester City manager Roberto Mancini claims his team are being victimised after Samir Nasri was sent off for a head-butt in the champions' 4-3 win at Norwich. The Italian was unhappy with the decision of referee Mike Jones to show Nasri a red card following a clash of heads with Norwich defender Sebastien Bassong, who was only booked for his part in the first-half incident at Carrow Road. Mancini has already been asked by the Football Association to explain comments after the 1-0 defeat at Sunderland last Wednesday that referee Kevin Friend "ate too much for Christmas". City will appeal against Nasri's red card, which threatens to result in a three-match ban, but whether the governing body will be impressed by Mancini's conspiracy theory claims remains to be seen. "Both players came forward with their heads, so if you are going to send off one, then you have to send off both, not only Samir," he said. "Samir said he touched his head, OK, but the other player has done the same. The linesman has a big responsibility also, because it was not a good decision. It is incredible. "You want to send off both players? Then, OK, the referee was there, he saw everything. The linesman was behind the players, he could not see. We will appeal, sure." Mancini admitted that Nasri had only himself to blame for reacting so angrily to Bassong's challenge a minute before the break, but he suggested City were treated with less leniency than other teams. "I am disappointed with Samir, and he will pay his fine, but the decision was not correct," the manager said. "Samir did a mistake, OK, but after why when the other player did the same thing, does he [the ref] send off only one? But there are two rules for different teams, and I hate this in football and cannot accept this. "In life, there is only one rule for everyone. This season, I have seen things which are not good. "For the referees, this is the most easiest thing to do, but I do not want to talk about the referees too much, because I said last time that they had a big lunch for Christmas, and I don't know what will happen." Edin Dzeko scored twice in the first four minutes before Anthony Pilkington pulled one back for Norwich after a quarter of an hour with a free kick that took a deflection off Gael Clichy. Sergio Aguero put the 10 men 3-1 up five minutes into the second half and Dzeko saw his shot go in off a post and Norwich goalkeeper Mark Bunn after Russell Martin had pulled one back for the home side. Defender Martin scored Norwich's third as well but the champions held out for 15 minutes to claim all three points. Norwich manager Chris Hughton was also adamant that referee Jones had made a costly error, although it was a tackle by Vincent Kompany in the build-up to Dzeko's second goal that had attracted his wrath. "I was very disappointed with their second goal," he said. "Not that I thought it was a booking but that type of challenge is always given as a foul these days."