Syria suggested Friday it may not cooperate with a planned international tribunal to prosecute the suspected killers of Lebanese Prime Minister Rafik Hariri because Damascus was not consulted on the plan, according to a letter circulated at the UN An ongoing UN investigation into the February 2005 truck bombing that killed Hariri and 22 others has said the killing's complexity suggested the Syrian and Lebanese intelligence services played a role in the assassination. Syria, which has denied involvement, said in a letter circulated Friday at UN headquarters that the tribunal should not be arranged until after the investigation is finished. It announced that hasty adoption of the court's statute "will firmly establish our belief that Syria has no connection with this tribunal." "In the event that the statute of the tribunal is adopted, unacceptable transgressions that undermine the sovereignty of certain member states and the rights of their subjects are likely to transpire," Syria wrote. The Syrian government continues to cooperate in the investigation, the letter added. The document, addressed to Secretary-General Kofi Annan, was dated Tuesday, when the Security Council authorized Annan to ratify an agreement by the UN and the Lebanese government on creation of the tribunal. The court would sit outside Lebanon, and a majority of judges as well as the prosecutor would be from other nations. The Lebanese government must now make the final decision on establishment of the court. On Nov. 13, Lebanese Prime Minister Fuad Saniora's Council of Ministers approved the tribunal plan but pro-Syrian President Emile Lahoud challenged the decision. Saniora has called for a Cabinet session on Saturday to approve the proposed court. The Syrian mission to the United Nations said no officials were available for comment Friday afternoon. On Wednesday, the Security Council approved a request from Lebanon for UN investigators already probing Hariri's assassination to assist the government's investigation of the latest killing. The council acted just hours after Secretary-General Kofi Annan sent a letter informing members that Prime Minister Fuad Saniora wanted "technical assistance" from the UN investigation commission in his government's investigation of Tuesday's killing of Industry Minister Pierre Gemayel. The first UN chief investigator, Germany's Detlev Mehlis, said the complexity of Hariri's killing suggested the Syrian and Lebanese intelligence services played a role in Hariri's assassination. In one report, Mehlis implicated Brig. Gen. Assaf Shawkat, Syria's military intelligence chief and the brother-in-law of Syrian President Bashar Assad. His successor, Belgian Judge Serge Brammertz, has avoided naming anyone but has described a very complex operation and said he is following many new leads. Four Lebanese generals, top pro-Syrian security chiefs under Lahoud including his Presidential Guard commander, have been under arrest for 14 months, accused of involvement in Hariri's murder. Pro-government groups in Lebanon, who accuse Syria in the slaying of Gemayel and other anti-Syrian figures, have warned that more government ministers may be targeted for assassination to deny the Cabinet the legal two-thirds quorum of 16 needed to approve the court. Syria has denied the accusations and condemned the killing.