Updated

Several hundred flag-waving Syrians protested near the U.S. Embassy on Tuesday, pledging support for their president and insisting their government was innocent of the assassination of Lebanon's former prime minister.

The demonstration came a day after the U.N. Security Council (search) unanimously passed a strongly worded resolution demanding that Syria fully cooperate with U.N. investigators looking into the slaying of Rafik Hariri (search).

"We are not criminals. We are not terrorists. We just need peace," one protester declared on the podium in al-Rawda square as patriotic songs blared from a loudspeaker.

The resolution, co-sponsored by the United States, Britain and France, warned that "further measures" were possible if Syria didn't cooperate with the U.N. inquiry headed by German prosecutor Detlev Mehlis (search).

In an initial report to the Security Council, Mehlis concluded Hariri could not have been killed without the complicity of Syrian and Lebanese intelligence. He also accused the Syrian government of "limited" cooperation with the investigation.

The Security Council gave new authority to Mehlis, who returned Monday to Lebanon amid tight security. The resolution requires Syria to detain anyone whom the U.N. investigators consider to be a suspect and allows them to determine the location and conditions under which the individual would be questioned.

Mehlis, whose mandate has been extended to Dec. 15, is likely to seek to question Syrian President Bashar Assad's (search) brother and brother-in-law, who were named in the report submitted Oct. 28.

An estimated 300 people took part in Tuesday's protest. It was organized by a private group called the Syrian Committee for Public Relations, but spontaneous demonstrations are extremely rare in Syria without state authorization.

Two nursing students, Yasmin Hassoun, 20, and Dina al-Awar, 19, said they came to express their support for Assad.

"The Security Council resolution was unjust. Syria could not have possibly betrayed Lebanon," said Hassoun, clutching a Syrian flag. She added she was not worried about possible U.N. action against her country, saying: "We have done nothing wrong."

The head of the organizers, Nizar Mayhoub, said the rally was intended to protest the increasingly heavy international pressure on Syria, as well as to demonstrate against what he called intervention in Syria's internal affairs and the "politicization" of the Mehlis report.

Mayhoub said the protest venue was chosen because the square leads to many embassies and was not intended to target the U.S. Embassy in particular. The square is also near the U.S. ambassador's residence.

U.S. Ambassador Margaret Scobey was recalled to Washington shortly after Hariri's assassination, which many Lebanese have blamed on Syria.

Lebanese President Emile Lahoud (search) said he hoped the U.N. resolution would help uncover the details of Hariri's killing and provide "tangible evidence that specifies the identity of those who planned, executed and helped carry out the crime."

Lahoud, who is pro-Syrian, said Lebanon would continue to cooperate fully with the U.N. commission "so it can continue its work in a professional and objective way."

Hariri and 20 others were killed in a massive car bombing in Beirut on Feb. 14. While Syria has rejected accusations of its involvement, it buckled under international pressure and withdrew its soldiers from Lebanon in April, ending a 29-year presence in its smaller neighbor.

On Monday, Syrian Foreign Minister Farouk al-Sharaa (search) angrily rejected the Security Council resolution, saying that accusing Syrian security forces of having advance knowledge of Hariri's killing was tantamount to saying U.S. officials knew ahead of time about the Sept. 11, 2001, attacks or that Britain knew about this summer's London transit bombings.

He also raised questions about why Britain had trained for similar scenarios soon before the London attacks.

"We know that such security organs, particularly the British, were fully aware that such attacks would take place and had prior training to face up to them," al-Sharaa said, jabbing his finger toward British Foreign Minister Jack Straw as U.S. Secretary of State Condoleezza Rice (search) and other foreign ministers looked on.

Al-Sharaa's reaction visibly angered Straw, who called it "absurd" and "the most grotesque and insensitive comparison."

Straw said any council member concerned about adopting the resolution under a U.N. charter provision which is militarily enforceable should have had their misgivings allayed by al-Sharaa's response.

Rice called al-Sharaa's outburst "a tirade which made the most bizarre connection." She said al-Sharaa's intransigence showed Syria wanted to discredit the U.N. inquiry even after a Security Council vote strongly supported it.