UNITED NATIONS – The assassination of a newspaper publisher and leading anti-Syrian lawmaker raises the stakes in the battle for a free Lebanon just as the showdown between Syria and the United Nations is coming to a head.

The brutal killing of Gibran Tueni, who died yesterday with three others when a massive bomb exploded in the Christian Beirut suburb of Mkalles, also has led to renewed calls for a comprehensive Lebanese strategy beyond solving the murder mystery of a former prime minister, Rafik Hariri, according to diplomats involved in Lebanon’s struggle to be freed of Damascus’s yoke.

There are links between the Hariri murder and yesterday’s blast that killed Tueni, a member of parliament and the publisher of the Lebanese daily al-Nahar. Tueni had been interviewed as a witness by the U.N. commission probing the Hariri assassination, German investigator Detlev Mehlis told The New York Sun yesterday.

Mr. Mehlis wrote in a report circulated among members of the Security Council yesterday that his team has helped the Lebanese authorities investigate “other bombings” besides the February 14 assassination of Hariri, which has been its main focus. He also described Syrian efforts to “create public disorder” in Lebanon.

“It’s horrible, horrible, horrible, especially since I have met him. He was a witness,” the Security Council-appointed leader of the Hariri investigation, Mr. Mehlis, told the Sun when asked about Tueni’s killing. Mr. Mehlis declined to comment about possible links between yesterday’s killing and the release of his report yesterday. “Speculations won’t help anyone,” he said.

According to the Daily Telegraph, the blast blew Tueni’s armor-plated vehicle into a ravine. His wife, Siham, rushed into the ravine, where Red Cross workers recovered his body from the smoking wreckage.

In Washington, President Bush said that the assassination was “yet another act of violence aimed at subjugating Lebanon to Syrian domination and silencing the Lebanese press.” Mr. Bush also urged Damascus to end “its interference in Lebanon once and for all.”

The Lebanese Cabinet last night formally called on the Security Council to widen the Hariri investigation to include other assassinations as well, leading to a rift with five pro-Syrians who temporarily suspended their Cabinet membership. The decision reflected a growing sense in Lebanon that the Hariri investigation can no longer be addressed separately from other events in the country.

In yesterday’s report, Mr. Mehlis wrote that after the Hariri assassination, a “high level Syrian official supplied arms and ammunition to groups and individuals in Lebanon in order to create public disorder in response to any accusations of Syrian involvement in the Hariri assassination.”

The report also said five unnamed “high ranking Syrian officials” were interviewed in Vienna recently as suspects involved in the Hariri assassination, and a sixth official had not yet been interviewed. According to published reports, confirmed yesterday by a diplomat close to the investigation, the sixth suspect is President al-Assad’s brother-in-law, Assef Shawkat, who is one of the most powerful men in Damascus.

Tueni recently told a French television station that as long as the current Baath regime remains in power in Damascus, Lebanon cannot emerge out of its shadows.

Until now, the Lebanese government wanted to concentrate on the Hariri investigation, putting off dealing with other major issues mentioned in Security Council resolutions, a Western diplomat familiar with the country told the Sun. Disarming militias such as Hezbollah, or dealing with the remains of Syrian intelligence influencing events inside the country, had to wait.

“It seems that now there is a more comprehensive view,” the diplomat said, requesting for anonymity because of his sensitive position.

Lebanese journalists yesterday vowed to continue to speak out despite a wave of assassinations of journalists and of those who voice opposition to Syria.

“There is a massive feeling of anger that every bad thing that happens here happens to journalists,” said a reporter for the English-language newspaper Daily Star, Leila Hatoum.

In a phone conversation from Beirut, Ms. Hatoum added, “You can’t be afraid to tell the truth, or else you’d go backwards.” She referred to the days – not long ago – that Syria wielded heavy influence over the Lebanese press.

In a nudge toward Syria, the Security Council yesterday called Tueni “a patriot who was an outspoken symbol of freedom and the sovereignty and political independence of Lebanon.” Those responsible for “today’s and previous” assassinations will be “held accountable for their crimes,” the council vowed in a statement.

French and American diplomats declined to say whether details in Mr. Mehlis’s report were enough to activate measures already decided on by the council, including sanctions against Lebanese or Syrian individuals found by the international investigators to be responsible for the Hariri assassination.

“The Security Council will not be intimidated,” America’s U.N. ambassador, John Bolton, told reporters yesterday as the council began deliberating on the latest Mehlis report.

The report detailed what Mr. Bolton called “obstruction of justice” by Syrian officials who, according to two witnesses, are considered suspects by the Mehlis team and have burned all intelligence documents related to Lebanon. It also said that the family of a witness, Hussam Taher Hussam, whose now recanted testimony was damaging to Damascus, had been intimidated by Syria.

“That is not cooperation, ladies and gentlemen; that is obstruction of justice by the government of Syria,” Mr. Bolton said.

But in a signal that there will be opposition on the council, its Arab member, Algerian Ambassador Abdallah Baali, said that according to the report, Syria has cooperated.

“We have fully cooperated,” the Syrian ambassador, Fayssal Mekdad, added. “This investigation has to be professional and has to be fair.”