"Details to be announced after the conclusion of the Test," the ICC said on Twitter.
Ishant and Prasad faced off during the final session of the fourth day when Ishant, after being bounced several times by Prasad, smacked his helmet repeatedly while running down the pitch, as if asking the bowler to aim at his head. Chandimal walked over from slip, his shoulder brushing Ishant's, and exchanged words with the batsman.
Once India's innings ended and as Ishant ran back to the dressing room to get ready to bowl, Prasad followed him at a full sprint all the way back. These two incidents were the flash points of an ill-tempered passage of play that involved several stares and words being exchanged between Ishant and Sri Lanka's players.
There was further tension when Ishant gave Upul Tharanga an angry send-off and then went on to celebrate Chandimal's dismissal by striking the side of his own head repeatedly.
Ishant had been docked 65% of his match fee at the end of the second Test for send-offs to Thirimanne and Chandimal. Thirimanne, too, was fined 30% of his match fee for showing dissent at the umpire's decision during the second Test.