BEIRUT: Lebanon braced for a fresh crisis Friday after Hezbollah urged a boycott of a UN-backed probe into ex-premier Rafiq Hariri's murder, spurring Washington to accuse the militant Shiite group of “intimidation.” Hezbollah leader Hassan Nasrallah warned all Lebanese in a solemn speech Thursday not to assist investigators probing the 2005 assassination of Hariri, saying that such cooperation would be tantamount to an attack on his movement. Prime Minister Saad Hariri, son of the slain Sunni five-time premier, later sought to calm tensions, while the United States vowed its support for the probe by the Special Tribunal for Lebanon (STL). “Nasrallah's remarks are an indication of how Hezbollah does not have the interest of all the Lebanese people in mind,” US State Department spokesman Philip Crowley told reporters in Washington. “It has a narrow agenda and we will do everything that we can to help the Lebanese government and Lebanese people resist this obvious intimidation,” he said. Crowley called the STL “vitally important” for the country's future, but rejected accusations that the United States wanted to influence its findings. In a terse statement, Nasrallah warned “citizens and politicians alike” that further collaboration with the tribunal would be tantamount to an attack on his group, which is backed by Tehran and Damascus. But Saad Hariri stressed late Friday that Lebanon was a “place of egalitarian coexistence between Christians and Muslims” that “will not fall into discord,” in a statement from his office. Hariri's office had earlier said there was no turning back on the STL after a meeting of his bloc, which with its allies holds the majority in the parliament. “The bloc emphasises its adherence to the tribunal, which has received consensus among the Lebanese as a form of protection of political pluralism,” it said in a statement. “The Lebanese constitution stipulates that Lebanon must respect all conventions of international legitimacy.” Tensions over the STL have been mounting in the turbulent Mediterranean country since reports emerged that the tribunal was likely to indict senior Hezbollah figures. The Shiite leader has repeatedly said he expects the STL to accuse his movement and that such an outcome would have repercussions, without specifying. Nasrallah's latest comments, which came hours after the United Nations warned Lebanon had entered a “hyper-dangerous” state, raised fears of the collapse of Lebanon's hard-won government, in which Hezbollah has two ministers. His speech in which he accused the STL of being a channel for Israeli intelligence came one day after two investigators were attacked by women at a gynaecology clinic in a Hezbollah-controlled southern suburb of Beirut.