Senior Lebanese officials on Friday rejected a U.N. report blaming of Syria (search) for tensions that led to the slaying of former premier Rafik Hariri (search), saying the U.N. mission exceeded its authority in accusing the government of negligence.

The report from a U.N. fact-finding mission was sharply critical of Syria and its allied Lebanese government. It said there was evidence Syria's president threatened Hariri with physical harm and that the Beirut government showed a lack of commitment to finding out who killed him, bungling and outright manipulating the investigation.

Many Lebanese blame Syria and the Lebanese government for the slaying of Hariri — an opponent of Syrian domination — in a Feb. 14 bombing that killed 17 others on a Beirut seafront street. Damascus (search) and Beirut vehemently deny any role in the killing.

The report stopped short of blaming Syria in the killing, but did say it was to blame for the political tensions in the country before Hariri's death.

Lebanese Foreign Minister Mahmoud Hammoud (search) said the U.N. fact-finding team, whose report was released Thursday, had gone beyond its mandate.

"The (U.N.) mission had no authority to allow it to reach these conclusions," he said. "We see this as infringement on the role of the Lebanese government."

Still, he insisted that the government "welcomes all means" to find the truth about the bombing.

Lebanese President Emile Lahoud urged U.N. Secretary-General Kofi Annan late Thursday to do "what is necessary" to uncover the truth behind Hariri's assassination, signaling Lebanon's acceptance of an international inquiry it had been persistently rejecting since the bombing.

The U.N. report does not directly assign blame for Hariri's death. But it did say that "it is clear that the assassination took place in a political and security context marked by an acute polarization around the Syrian influence in Lebanon."

Hammoud rejected this, saying tensions were caused by the United Nations' calling for Syria to withdraw its troops from Lebanon in Resolution 1559.

"We say that tension began when signals starting coming from abroad that a resolution was to be issued by the Security Council — it later became 1559 — this resolution pushed the atmosphere toward political polarization," Hammoud said.

Justice Minister Adnan Addoum stressed that the U.N. report was not a legal opinion and rejected claims of evidence tampering. "We consider it a technical, security document and it cannot be considered a legal and judicial document," he told the same news conference.

Still, Interior Minister Suleiman Franjieh acknowledged "flaws" in the security system as the report noted.

The report says there was a "distinct lack of commitment" by the authorities to investigate the crime, and it detailed a host of flaws, including the disappearance of crucial evidence and tampering with the scene of the blast. Parts of a pickup truck were brought to the scene, placed in the crater and photographed as evidence, it said.

Syrian military intelligence shares responsibility with Lebanese security forces for failing to provide "security, protection, law and order" in Lebanon, the report said.

"This is far from reality," Hammoud said.

Addoum denied that car parts were placed in the crater. "The proof is that the wreckage of the car was found in the sea near the site and was retrieved by divers from the international experts," he said.

The U.N. report said the blast was caused by a surface explosion of about a ton of TNT. The government has contended a suicide car bombing struck Hariri's motorcade.