WASHINGTON: The United States on Wednesday again urged Lebanon to work with a UN-backed tribunal, which says it has enough evidence to try four Hezbollah members in the assassination of former premier Rafik Hariri.

The call came after the Special Tribunal for Lebanon unsealed the indictment of the four men and said the evidence was sufficient to go to trial over the February 2005 car bombing that killed Hariri and 22 others.

State Department spokeswoman Victoria Nuland, recalling remarks made last month by Secretary of State Hillary Clinton, said the indictment was an "important milestone" in Lebanon's quest to put an end to political violence.

"We appreciate the work of the Special Tribunal and call on the government of Lebanon to continue to meet its obligations under international law to support the Special Tribunal," Nuland said.

"This process is a means of ending the era of impunity for the terrible and tragic violence that has touched all of Lebanon's communities."     Prosecutors had previously confirmed that they were indicting the four suspects -- all Lebanese citizens -- over the massive attack in Beirut. All remain at large.

Lebanese officials have said the four are members of the Shiite militant group, but the indictment stopped short of openly drawing the connection.

Hezbollah leader Hassan Nasrallah, whose organization is now a key player in Lebanon's coalition government, said Wednesday the Netherlands-based tribunal lacked the proper evidence to implicate the four men.

Hezbollah, a vociferous foe of Israel, is supported by Syria and Iran and is considered a terrorist organization by the United States.