A group of monks led by the JHU or the Heritage Party stormed the Sri Lankan President's office area in central Colombo Friday afternoon by breaking security barricades.
The demonstrating monks threatened to set themselves ablaze unless a presidential emissary made a pledge on behalf of Kumaratunga to abandon the plan which they allege gives recognition to a terrorist group.
The police used water cannon and tear gas when the unruly monks attempted to break the barricades within the immediate precincts of the President's House.
At least three monks were admitted to the national hospital for injuries during the clash with the police.
The Sri Lankan president at the time was having a crisis meeting with the Chief Monks of three Buddhist sects.
A statement issued after the meeting said the president informed the leading monks that her plan was not a threat to Sri Lanka's territorial integrity or sovereignty.
She would, however, consult them before a final decision could be made. So far no final decision has been made on the date for the signing of the mechanism with the Liberation Tigers of Tamil Eelam (LTTE).
Earlier in the day the JHU rejected a request from the president to make their fasting monk Ven Omalpe Sobhitha to give up his fast to death which had entered its fifth day in the central town of Kandy.
Also on Friday, the president's main coalition partner, the JVP or the People's Liberation Front announced that they would be leaving the government on June 16 unless the president decided to give up her plan by midnight on June 15.