Beirut: The UN warned it may send a verification team back to Lebanon following reports that the Syrian intelligence apparatus may not have completely withdrawn from the country.

Speaking last night, Secretary General Kofi Annan said: "We are now receiving reports that there may be elements that are still there, and we are considering the possible return of the verification team to ascertain what is going on."

The move comes just days after the murder of anti-Syrian journalist Samir Kassir, which Lebanon's political opposition has accused Syria of being involved in.

Damascus had denied any role in the assassination, and also insists it has complied with UN Security Council Resolution 1559 and fully withdrawn its troops and security apparatus from Lebanon.

But leading Lebanese opposition figure Walid Jumblatt insisted during a television interview last night that "tens of Syrian intelligence officers are still running free" in the country.

Jumblatt also said he was afraid of an assassination attempt on his own life, and added he held the Syrian leadership responsible for any further deterioration of security in Lebanon.

The UN had sent a verification mission to the country to check on the pullout of Syrian troops from Lebanon last May.

The team reported on May 23 that Syria had "fully" withdrawn troops in compliance with UN Resolution 1559 steered through the Security Council last September by France and the United States.

The mission also said it had found no remaining trace of the Syrian intelligence services, but added that the clandestine nature of such agencies made it difficult to establish their complete withdrawal.

Syria's withdrawal from Lebanon came in the wake of the assassination of former Premier Rafik Hariri, which sparked wide anti-Syrian protests around the country and increased international pressure for Damascus to comply with Resolution 1559.

United Nations special envoy to the Middle East, Terje Roed-Larsen, is scheduled to meet with Syrian President Bashar Assad in Damascus this weekend.

Annan said: "Roed-Larsen will have discussions with Assad on developments on the ground and will report back to me next week."

The UN resolution, which was issued last September, calls in addition to the withdrawal of all foreign troops from Lebanon, to the disarmament of Lebanese and non-Lebanese militias in the country.

This has been building pressure on Hizbullah to disarm. But Hizbullah officials and Lebanese politicians have been insisting this is an internal Lebanese issue that will be solved through dialogue.

Syrian troops first entered Lebanon one year after the start of the Lebanese Civil War which erupted in 1975.

At one point there were more than 30,000 Syrian troops based in the country. Last year the number fell to around 14,000 before they finally departed in April.