WASHINGTON — The United States recalled its ambassador and considered further sanctions against Syria yesterday, a day after the fiery assassination of former Lebanese Prime Minister Rafik Hariri in downtown Beirut.

The actions signaled that after months of growing tensions over its alleged role in the Iraqi insurgency and other disputes, the Bush administration intends to use Hariri's death to press demands that Syria withdraw its troops from Lebanon and stop supporting terrorism, even without proof that Syria was involved in the assassination.

Secretary of State Condoleezza Rice ordered U.S. Ambassador Margaret Scobey to return to Washington. Scobey also delivered a strongly worded rebuke to the regime of President Bashar Assad for failing to comply with a U.N. resolution that calls for the withdrawal of all Syrian military forces from Lebanon.

Rice said yesterday that the United States has a "growing list of differences" with Syria.

Rice and President Bush are considering additional economic and diplomatic sanctions beyond those the president ordered last May, said a State Department officials, who requested anonymity to speak more freely.

Hariri's assassination by a powerful car bomb Monday has raised fears of new sectarian violence in Lebanon, which has been relatively peaceful since its 15-year civil war ended in 1990.

Hariri's backers charged through Beirut and at least two other cities yesterday, chanting slogans against Syria, the primary power broker in Lebanon.

Syria deployed thousands of troops in Lebanon shortly after the outbreak of civil war in 1976 and refused to leave after the war ended in 1990, despite international pressure. In part because of its military presence, Syria has also had virtual veto power over many aspects of Lebanon's political system.

Syria has denied a role in Hariri's killing, and no definitive proof of responsibility has emerged. U.S. officials said they had no evidence of Syrian complicity in Hariri's assassination.

Instead, State Department spokesman Richard Boucher advanced the argument that the killing undercuts Syria's stated reason for keeping 14,000 troops in Lebanon: to maintain the multiethnic country's stability.

"The very tragic bombing yesterday shows that that's just plain not true," he said. "And therefore we believe that there is no reason for them to remain there."

Boucher repeated U.S. complaints that Syria had not been helpful in Iraq and had harbored anti-Israeli terrorists in Damascus, and he demanded that Syria withdraw from Lebanon.

Syria, despite providing intelligence help on al-Qaida after Sept. 11, has been at odds with the United States for allegedly harboring top-level Iraqi fugitives involved in the insurgency there. It has also been a target of Israel's supporters in the United States for its longtime support of Palestinian militants as well as Hezbollah (Party of God), a Lebanese Shiite group that repeatedly attacked Israeli forces until they withdrew from southern Lebanon.

Imad Moustapha, the Syrian ambassador to Washington, said the assassination was a "sinister plot" against Syria. He said he did not have any immediate orders to return home to counter the U.S. move.

In September, the U.N. Security Council passed a resolution demanding that Syria withdraw its troops from Lebanon. The United States and France sponsored the measure.

The Bush administration has used diplomacy to try to get Syria to acquiesce and to halt the use of its territory by supporters of the insurgency in Iraq.

Bush harshly criticized Syria in his State of the Union address two weeks ago, and, acting under a 2003 law passed by Congress, imposed largely symbolic sanctions on Syria last May, including a flight ban on Syrian aircraft and a prohibition of exports other than food and medicine.

Separately, he ordered U.S. financial institutions to cut ties with the Commercial Bank of Syria because of money-laundering concerns, and froze assets in the United States that belong to Syrian individuals and government entities.

Egyptian Foreign Minister Ahmed Abul-Gheit, in Washington yesterday for meetings with Rice and others, said that Syria had been helping to convince Palestinian factions to abide by an informal cease-fire with Israel.

AP Syrian Vice President Abdul-Halim Khaddam, center, listens to Bahaa Hariri, son of the slain former prime minister, left, and Lebanese parliament speaker Nabih Berri, at a memorial service yesterday.

Abul-Gheit, speaking at the private Brookings Institution, expressed concern that a cycle of killings and retaliations in Lebanon might cause it to "slide into a situation that resembles ... the mid-'70s, when we had the civil war."

That civil war erupted among exiled armed Palestinian groups, radicalized Muslim groups and the ruling Christian faction.

Although most suspicion for the assassination has fallen on Syria or its supporters in Lebanon, it was clear the possibilities also might include rogue Syrian intelligence operatives, or even factions among the country's myriad religious groups. Claims of responsibility by Islamic militants also raised the possibility that Hariri had been targeted because of his close ties to Saudi Arabia — a top enemy of al-Qaida and other groups.

Allies of Hariri, who resigned in October to protest an extension in office for pro-Syrian President Emile Lahoud, protested in Lebanese cities yesterday and blamed Syria for the killing. The Lebanese army went on alert.

On Monday night, a mob attacked the offices of the Lebanese chapter of Syria's ruling Baath party in Beirut with stones and set fire to shacks used to exchange money and sell cigarettes in front of it.

The Lebanese government said the explosion that killed Hariri and incinerated his motorcade almost certainly was caused by a suicide car bomb. Police said the toll from the bombing was 14 dead and about 120 injured.

A claim of responsibility by a previously unknown Islamic militant group — Support and Jihad in Syria and Lebanon — was not considered credible, with Justice Minister Adnan Addoum warning it could be an attempt "to mislead the investigation."

Compiled from Knight Ridder Newspapers, The Associated Press, Newsday and The Washington Post.