UNITED NATIONS – Syria is believed responsible for yesterday’s assassination of Rafik Hariri, a Lebanese power broker who has recently used his extensive international connections to solidify a political bloc to fight for Lebanese independence, many leaders in the region and in world capitals said.

The White House called the assassination of the former prime minister in downtown Beirut “an attempt to stifle these efforts to build an independent, sovereign Lebanon free of foreign domination.” France called for an international investigation. Lebanese dissidents and Washington legislators pointed directly at Syria, as did many in Jerusalem.

A number of Lebanese and others in the Middle East told The New York Sun yesterday that in the last few days, Hariri had stepped up his opposition to his major political rival, President Lahoud, who is backed by Syria, and formed a powerful coalition with Druze leader Walid Jumblatt and the Maronite-Christian archbishop, Cardinal Nasrallah Botrous Safir, to create a political bloc that would run pro-independence candidates in the upcoming general election, expected in May.

The coalition, which aims to win a majority in Parliament and then run its own presidential candidates, is backed by America as well as Saudi Arabia and France, which retains considerable influence over its former colonies, Syria and Lebanon. Last fall, Washington and Paris surprised many diplomats when they formed an alliance to unite the Security Council behind a resolution calling on all foreign forces to leave Lebanon.

The multibillionaire Hariri, who was a close friend and financial backer of President Chirac, was perceived in Beirut and Damascus as the main force behind the influential U.N. resolution no. 1559, which was passed last September after a Syrian-backed maneuver to extend the term in office of Hariri’s nemesis, Mr. Lahoud, violating Lebanon’s constitution.

Hariri was summoned to Syria at the time, and later expressed public opposition to the resolution. Shortly after his return, a Druze ally, Marwan Hamadi, a former Cabinet minister, was badly injured by a car bomb that at the time was universally described as a Syrian warning shot to Hariri.

At least 10 people were killed and more than 100 injured in yesterday’s explosion, which gouged a crater in the street 30 feet wide and 9 feet deep, shattered windows, and twisted metal window frames at a nearby British bank and the landmark Phoenicia Hotel, the Associated Press reported. More than 650 pounds of TNT was used in the bombing, according to security officials in Beirut.

Syria publicly condemned the assassination. A formerly unknown group, Support and Jihad in Syria and Lebanon, took responsibility, and the Lebanese information minister, Elie Ferzli, told CNN that a suspect with links to extremists was in custody. But many in the region pointed to Damascus.

“A small group could not have done this,” a former Lebanese prime minister, Michel Aoun, told the Sun by telephone from France. “I don’t know who has these systems, but you need government capabilities to do this.”

Rep. Eliot Engel, a Democrat of New York who was one of the sponsors of the Syrian Accountability Act, which threatens Damascus with sanctions unless it stops supporting terrorism and ends its occupation of Lebanon, agreed. “I would not be surprised if Syria is behind today’s bombing to release growing international pressure for it to withdraw completely from Lebanon,” he told the Sun.

France called for an international investigation. Mr. Chirac said in a statement that Hariri embodied “the indefatigable will of independence, freedom, and democracy.” Minutes before receiving the news, Mr. Chirac hosted the Israeli foreign minister, Silvan Shalom, telling him, “Syria has a negative influence over the democratization process of Lebanon,” according to the Israeli Web site Y-net.

The consensus in Jerusalem was that Syria has finally had enough of international pressure and Lebanese attempts to get Syria to withdraw the 30,000 troops stationed in the country. Mr. Hariri was “the bulwark for the anti-Syrian opposition,” a Knesset member with the dovish Labor Party and a former general, Ephraim Sneh, said. “Syria has never changed its tactics,” he told the Sun, pointing to a history of assassinations since the 1970s of Druze and Christian Lebanese leaders who strayed from the pro-Syrian line.

Hariri’s decision to finally join up with Mr. Jumblatt and Cardinal Safir was seen by many in Lebanon as the main trigger for the assassination. “Hariri made up his mind in the last day or two,” the president of the pro-democracy group United States Committee for a Free Lebanon, Ziad Abdelnour, told the Sun.

He described the group of Druze and Christians, which along with Hariri, a Sunni, publicly supported resolution 1559, pushed for the Lebanese army to take over the southern part of the country, now occupied by the terrorist group Hezbollah, and eventually planned to negotiate with Israel as well. The agenda, he said, was reflective of the growing anti-Syrian mood in the country.

“They decided to team up for true independence of Lebanon,” Mr. Abdelnour said, adding that the move was strongly backed by Washington, Paris, and Riyadh. “Hariri was a major catalyst for change, and the Syrians decided to spoil everything for the Americans.”

At the Security Council, an American-French draft statement was circulated yesterday and is expected to pass today. It denounced the assassination, “which took place in the context of on going effort by the people of Lebanon to solidify Lebanon’s democracy, including the upcoming general election.” It also called on Secretary-General Annan to make a report “urgently.”

Washington yesterday indicated that the statement may not be the last act of the council. A White House spokesman, Scott McClellan, said America “will consult with other governments in the region and on the Security Council” about measures to punish those responsible, and also “to end the use of violence and intimidation against the Lebanese people, and to restore Lebanon’s independence, sovereignty, and democracy by freeing it from foreign occupation.”

Secretary of State Rice spoke with Mr. Annan on the telephone, discussing ways to implement resolution 1559. Recently, the secretary-general nominated his longtime Middle East envoy, Terje Roed-Larsen, as his representative to implement the resolution. Mr. Larsen, in fact, left Damascus and Beirut only last Friday.

A retired U.N. official, Samir Sanbar, who keeps close ties at Turtle Bay and in his native Lebanon, said he believed it was that resolution that worried the Syrians more than anything.

“It was his foreign ties,” he said of Hariri, explaining the possible motive for the assassination. He said that Syria has a tight grip over Lebanon’s internal political forces. What it was mostly concerned about were players who can mobilize the outside world to add pressure. The Hariri assassination, he added, was meant as a signal to others.

The congressional Syrian Responsibility Act was also viewed as menacing by Syria, and its backers were adamant that they would not weaken. “Such acts of violence are calculated to violate the spread of free and democratic ideas,” Senator Santorum, a Republican of Pennsylvania who was one of the first sponsors of the legislation, told the Sun.

“The world must not take the bait,” added Mr. Engel. “We have to keep the pressure on. It’s time for Syria to get out of Lebanon.”

Mr. Abdelnour, who advocates a strong American line against Syria, compared Mr. Assad to Saddam Hussein. “You can’t get rid of one Baath regime and leave the other intact,” he said.