|Nasrallah's address comes a day after a crowd of women attacked two UN investigators from the tribunal [Reuters]
Hassan Nasrallah, the leader of the Hezbollah movement, has urged all Lebanese to boycott a UN-backed investigation into the murder of Rafiq Hariri, Lebanon's former prime minister.
In a televised address on Thursday, he warned that the country had reached "a very dangerous point".
"I call on all Lebanese, citizens and politicians alike, to boycott this tribunal and end all co-operation with its investigators.
"Any further co-operation with the tribunal is equal to an attack on the resistance," Nasrallah said, referring to his predominatly Shia Muslim movement.
Nasrallah's speech came one day after two investigators from the Special Tribunal for Lebanon were attacked by a group of women at a gynaecology clinic in a Hezbollah-controlled southern suburb of Beirut.
The investigators had requested information on patients from the clinic's head doctor and were leaving when about 30 women charged at the pair and snatched a briefcase from them.
The attack underscored the charged emotions behind the tribunal, which
Hezbollah says is biased.
Nasrallah did not address the violence at the clinic or whether Hezbollah had asked the crowd to gather, but he confirmed that the wives and relatives of Hezbollah commanders and officials were among the clinic's patients.
Lebanon is facing a crisis over The Hague-based tribunal as unconfirmed reports indicate it is set to accuse members of Hezbollah of involvement in Hariri's killing in a bombing in Beirut in 2005.
Nasrallah has confirmed several of members of his party, both male and female, have been interrogated in connection with the Hariri murder and has called for a local investigation instead.
Saad Hariri, Lebanon's prime minister and son of the slain former premier, has vowed to see the UN tribunal through.
In his speech, Nasrallah accused the tribunal of being another channel for Israeli intelligence.
"Every piece of information secured by investigators of this tribunal reaches the Israelis," he said.
Meanwhile, the United States expressed its growing frustration with Hezbollah and its patrons Iran and Syria.
Susan Rice, the US ambassador to the United Nations, said that Washington continues to have "deep concerns about Hezbollah's destructive and destabilising influence in the region."
|UN probe into Hariri killing could spark strife in Lebanon if Hezbollah members are implicated
She also accused Syria and Iran of trying to undermine Lebanon's independence and endanger its stability.
"We understand that certain actors within and outside Lebanon - including Syria, Hezbollah, and Iran - may believe that escalating sectarian tensions will help them assert their own authority over Lebanon. However, these actors serve only to destabilise Lebanon and the region," Rice said.
She singled out Syria for further rebuke.
"Syria, especially, has displayed flagrant disregard for the sovereignty, territorial integrity, unity, and political independence of Lebanon under the sole and exclusive authority of the Lebanese government, as affirmed in resolution 1559," she said.
UN Resolution 1559 was adopted in 2004, and called for the withdrawal of all foreign forces from Lebanon - which at the time were primarily Syrian - and reaffirmed its support for the country's sovereignty, territorial integrity and independence.
Syria has also criticised the Hariri tribunal by raising questions about its neutrality.
Earlier this month, Syria's judiciary issued arrest warrants against 33 Lebanese officials and foreigners for allegedly misleading the investigation, among them figures close to Saad Hariri and Detlev Mehlis, the first UN chief investigator.