Chelsea and Man City were fined following an on-field fracas in December

Chelsea were fined £100,000 for a mass player confrontation despite claims their "culture changed" under manager Antonio Conte, the Football Association has revealed.

An independent commission has disclosed why Chelsea and Manchester City were fined following a fracas on the pitch last month, in written reasons published by the FA.

Both clubs admitted a charge for failing to control their players in added time of the Premier League game on December 3 last year, but requested a personal hearing with the commission.

Chelsea won 3-1 at the Etihad Stadium, with Manchester City's Fernandinho and Sergio Aguero sent off during the fracas.

Chelsea were fined £100,000 and City sanctioned £35,000 for the same incident.

Sergio Aguero was sent off for a challenge on David Luiz

"The commission was not unanimous as to which party actually caused the mass confrontation," ruled the panel, chaired by Gareth Farrelly. "There was considerable deliberation as to whether the Sergio Aguero tackle [on David Luiz, which led to his sending-off] was the primary instigator of the incident or whether the Nathaniel Chalobah push [in the aftermath] was responsible."

The panel, which also included Udo Onwere and Ifeanyi Odogwu, decided by a majority that the nature of Aguero's tackle was the main reason for the confrontation.

Watch highlights of Manchester City 1-3 Chelsea Watch highlights of Manchester City 1-3 Chelsea

It was noted that Manchester City had a "previous unblemished record".

Jim Sturman QC, representing Chelsea, told the commission that: "...The culture of the club had changed under the new manager (Antonio Conte)."

Chelsea also argued: "...There was no sustained aggression and the incident did not last long. There was no disrespect shown to the referee and this incident was less serious than previous infractions."

Former Italy coach Antonio Conte took charge of Chelsea in the summer

Yousif Elagab, representing the FA, told the panel: "The FA to some degree understood the players' reactions but a key point of concern in this case was the fan involvement, and the fans being close to the field of play."

The commission ruled that both clubs were "equally culpable" as the game was a "high profile, top-of-the-table clash with a worldwide audience."

The written reasons do not reveal whether a points deduction was considered but the commission acknowledged that the prompt admission of guilt from both clubs reduced their punishment.

Chelsea received a higher fine after the panel considered six previous breaches of the same rule since 2011, worth nearly £500,000.