"The ministry has asked the High Commissioner Dr Chris Nonis to raise the issue with the British authorities", Rodney Perera, External Affairs Ministry spokesman said here.
He said the British Foreign Office would be asked to take appropriate measures to ensure the safety of the Lankan nationals in Britain.
The move came after alleged supporters of the LTTE had assaulted Sri Lankan fans at Cardiff immediately after Thursday's semi final clash with India in the on going ICC Champions Trophy cricket tournament.
At Cardiff, at least five LTTE supporters ran into the ground during the final over of the Sri Lankan innings. They were carrying LTTE flags around their necks.