BEIRUT (Reuters) - The United States demanded on Friday that Syria be held to account after a U.N. murder inquiry implicated senior Syrian officials in the bomb blast that killed former Lebanese Prime Minister Rafik al-Hariri. The probe led by German prosecutor Detlev Mehlis named as suspects in the February 14 killing members of Syrian President Bashar al-Assad's inner circle, including his brother-in-law. The U.N. report said Foreign Minister Farouq al-Shara gave investigators false information and it accused top pro-Syrian Lebanese officials of playing major role in the killing, with suspicion cast even on President Emile Lahoud. "Even an initial reading of the report is deeply troubling," U.S. Secretary of State Condoleezza Rice declared. "You have clearly a case in which there is an implication that Syrian officials were involved in the assassination of Rafik al-Hariri. You also have a clear indication that the Syrian government has not been cooperating. "These are charges that will lead the international community to have to seriously consider how it demand accountability," she added. Syria dismissed the report as "gossip" and the charges as "far from the truth," while Lahoud denied them and indicated he would resist calls for him to resign. Mehlis's report, submitted to the 15-nation Security Council, said there was probable cause to believe the decision to kill Hariri could not have been taken "without the approval of top-ranked Syrian security official(s)," nor carried out without the complicity of Lebanese security services. It said the investigation, now extended by U.N. Secretary-General Kofi Annan to December 15, was incomplete. However, it looked set to start the ball rolling for diplomatic action against Syria, already isolated over U.S.-led charges of meddling in Iraq and Lebanon. U.S. Ambassador John Bolton said he was consulting fellow Security Council members on possible responses, but he would not say whether sanctions against Syria was among them. DAMASCUS DENIES CHARGES Syrian Information Minister Mahdi Dakhl-Allah dismissed the U.N. findings as a political statement. "The report is far from the truth," he told Al Jazeera TV. "It was not professional and will not arrive at the truth but will be part of a deception and great tension in this region." Syria's ambassador to the United Nations, Imad Moustapha, told Reuters the Mehlis report was biased and unfair. "The report is full of political rumors, gossip and hearsay and it has not a single shred of evidence that will be accepted by any court of law. We are so disappointed with it," he said. Hariri was a strong critic of Syria's domination of Lebanon, and many Lebanese have long suspected a link between his killing and the Syrian authorities and their Lebanese allies. His death along with those of 20 other people in a truck bombing on Beirut's seafront sparked world outrage and Lebanese protests that forced Syria to end its 29-year military presence. According to one unidentified witness cited in the report, Assad's brother-in-law, Major General Asef Shawkat, and his brother, Maher al-Assad, were among a group of Syrian and Lebanese security officials who "decided to assassinate" Hariri in mid-September 2004 and then planned the murder during a series of meetings in Damascus. Their names were edited out of the final document but were visible in an earlier draft seen by Reuters. The report said the Syrian authorities, after initially hesitating to help, had cooperated "to a limited degree." But several individuals had tried to mislead investigators "by giving false or inaccurate statements," it said. Several anti-Syrian members of the Lebanese parliament called on Lahoud to step down. MP Jibran Tueini also accused Assad of ordering the murder. Assad insisted this week his country was "100 percent innocent" in the case. The report said a suspect "made a call minutes before the blast, at 1247 hrs" to Lahoud's mobile phone. Lahoud's press office denied the president took such a call and indicated he would not be forced from office. Rustom Ghazali, Syrian intelligence chief in Lebanon at the time, also appeared to have played a key role, the report said. It made similar charges against the four pro-Syrian Lebanese generals arrested and charged earlier in connection with Hariri's killing, on Mehlis' recommendation. Interior Minister Ghazi Kanaan died last week in what officials said was suicide, three weeks after he was questioned by investigators in his capacity as a witness in the case. Ahmed Jibril, head of the Damascus-based Popular Front for the Liberation of Palestine-General Command (PFLP-GC), denied the report's claims that it played a role in the assassination.