BEIRUT, Dec 17: The head of the UN probe into the slaying of Lebanon’s ex-premier Rafiq Hariri for the first time unequivocally accused Syria of being behind the assassination, in an interview published on Saturday.

Despite repeated Syrian denials of involvement, outgoing German magistrate Detlev Mehlis who has been heading the investigation since June, showed not a flicker of doubt that its ‘authorities’ were responsible.

Asked by the Arab daily Asharq al Awsat if he was ‘perfectly convinced of Syria’s responsibility in the murder of Hariri’, Mr Mehlis said: “Yes. The Syrian authorities are responsible.”

His comments are set to further ratchet up the pressure on Syrian President Bashar al Assad, coming just after the latest in a slew of killings of anti-Syrian critics that have hit Lebanon following the Hariri murder.

Mr Mehlis insisted that ‘there is a link between the attacks that hit Lebanon’ since Mr Hariri’s murder in February and the killing on Monday in a massive car bomb of anti-Syrian MP and press magnate Gibran Tueni.

Mr Mehlis, whose mandate ended on Thursday and is waiting for a replacement to be chosen, accused some parties of seeking ‘to deviate the course of the Investigation’, in a reference to Syrian witness Hussam Hussam.

A former Syrian intelligence officer, Mr Hussam initially told UN investigators that the brother and brother-in-law of Syrian President Bashar al Assad were implicated in the Hariri murder before recanting his testimony last month.

Mr Mehlis has released two reports since October on the Hariri murder implicating Syrian and Lebanese intelligence officers.

The second one, which coincided with Mr Tueni’s killing, cited fresh evidence of Syrian and Lebanese involvement and charged that Damascus was not cooperating in the probe.

However, Mr Mehlis’ comments in the newspaper interview were the first time he had so unambiguously pointed the finger at Syria.

The UN Security Council on Thursday renewed a call for Damascus to renew its cooperation with the probe and extended by six months its mandate, drawing international satisfaction.

“We’re satisfied with the step the Security Council took,” White House spokesman Sean McCormack told reporters.

“I don’t think the Syrian government should take any comfort in yesterday’s action ... (which) keeps the spotlight on Syria, keeps the spotlight on Syria’s failure to fully cooperate with this investigation,” he said.

“And if the Syrian government or others think that the world is going to simply turn away from this investigation and forget about getting to the bottom of who’s responsible for the murder of Prime Minister Hariri, they’re mistaken.”

In Brussels, the leaders of the 25-member European Union expressed their ‘deep concern’ over the conclusions of the second Mehlis report and urged Syria to ‘cooperate unconditionally’ with the probe.

They also denounced the ‘campaign of brutal’ assassinations in Lebanon over the past year.

Mr Tueni’s father added to the pressure on Damascus by announcing plans to sue Syria’s ambassador to the United Nations, Fayssal Mekdad, over derogatory comments about his son.

Veteran Lebanese diplomat Ghassan Tueni charged that Mr Mekdad compared his son to a ‘dog’ in comments reported on Wednesday by the US daily, The New York Sun.

“I will sue him before the American courts,” he said on Friday.

WIDENING OF PROBE: The New York-based Committee to Protect Journalists has called for an expansion of the Hariri probe to include attacks on Mr Tueni and fellow anti-Syrian journalists, including Samir Kassir who was killed in June.