In his latest report on the UN investigative commission, Belgian prosecutor Serge Brammertz said he had made progress on the Hariri investigation in recent months and was able to draw preliminary conclusions about important aspects and to identify more people involved.

Mr. Hariri and 22 others died in February, 2005, in a Beirut car bomb blast that early UN findings linked to Syrian and Lebanese security officials. Syria has denied involvement but the outcry forced it to withdraw its troops from Lebanon.

Since his last report in July, Mr. Brammertz said tension had been high in Lebanon, which is going through a protracted crisis over the election of a president to succeed pro-Syrian Emile Lahoud, whose term expired last week.

"The commission notes that evidence uncovered in the Mr. Hariri and some of the other attacks, including the recent assassination of Antoine Ghanem, confirms the fact that the perpetrators had and still have advanced and extensive operational capacities available in Beirut," Mr. Brammertz said.

Ghanem, an anti-Syrian Christian member of parliament, was among seven people killed by a car bomb in September.

Mr. Brammertz said the tense security environment was affecting the commission's work and warned that after the failure to elect a president last week, "the prospect of a rapid deterioration cannot be excluded."

Mr. Brammertz said the investigative commission needed to restrict the information it made public to avoid jeopardizing the probe and endangering individuals, and he recommended setting up a witness protection program.

He said recent developments had led to the identification of "additional persons of interest" but he gave no names.

"As a growing number of investigative projects are concluded and as the investigation narrows, the Commission has taken an increasingly cautious approach to the management of information linked to the investigation," said the report from Belgian prosecutor Serge Brammertz.

"The Commission has implemented a number of measures in this direction and has sought to avoid jeopardizing the integrity of the investigation and the legal process as well as the safety of individuals.

"As a result, the Commission is of the opinion that only limited information can be placed in the public domain regarding its ongoing investigation," he added.

"The Commission is actively preparing to hand over the results of its investigation to the Prosecutor of the Special Tribunal for Lebanon when the Tribunal starts functioning," he said.

Mr. Brammertz has said in the past that a likely motive for the attack was the role of Mr. Hariri, who became a prominent critic of Syria, in support of a 2004 UN resolution demanding that Syrian and other foreign troops withdraw from Lebanon.

In the latest report, he said Syria had been generally cooperative with the investigation.

Senior officials from Syria, which for three decades was the powerbroker in its smaller neighbor, have been implicated in the Hariri slaying.

Damascus strongly denies any connection with that murder as well as with the string of assassinations of other anti-Syrian Lebanese figures.

Last July, Brammertz released an interim report indicating that investigators had identified several people who may have been involved in Hariri's assassination

Mr. Brammertz also is investigating 18 other political murders or attempted murders in Lebanon and he said the commission would focus on establishing links to the Hariri case.

It was Mr. Brammertz's last report to the Security Council before his mandate expires at the end of this year, when he will be replaced by Canadian prosecutor Daniel Bellemare.

The commission is due to hand over its findings to a special tribunal that is being established in the Netherlands.

Starting Jan. 1, Mr. Brammertz will take over as prosecutor of the Hague-based international tribunal for former Yugoslavia, replacing Switzerland's Carla Del Ponte. His appointment was approved Wednesday by the UN. -With Agenices