England prop Ellis Genge revealed he had been subjected to death threats after footage surfaced of him apparently neglecting to clap the victorious Welsh players off the pitch following the match.
Genge wrote: "Don't know why I'm not clapping in that tunnel, must be deep in thought - utmost respect for the Welsh, as for keyboard warriors sending death threats etc..."
England Rugby issued a statement in which it urged "true rugby fans" to resist and reject such incidences of abuse.
The statement read: "Respect is a core value of rugby. Yesterday we lost to Wales who deserved their victory.
"Unfortunately, some of the reaction on social media to players and the team has not shown the level of respect the rugby community prides itself on.
"We will support our players and team against online abuse and hope true rugby fans will stand with us."
Earlier, England Rugby had sent its support to BBC reporter Sonja McLaughlan, who described how she had been reduced to tears after criticism of her post-match interviews.
Also on Twitter, England Rugby wrote: "Abuse for doing your job is not OK and we stand with you.
"We will see you for the next one. Hold your head high and know you have our support."
Additional reporting by PA.
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