Updated

The president of a U.N.-backed court seeking to prosecute the assassins of Lebanon's former prime minister Rafik Hariri urged Beirut authorities Thursday to step up efforts to arrest four men indicted for the 2005 suicide bombing.

Italian Judge Antonio Cassese said Lebanon must do more to help the tribunal "in searching for, serving, arresting, detaining and transferring the accused."

Lebanon's prosecutor general recently reported to the court that attempts to detain the four men, all members of the powerful Iran-backed Hezbollah militia, have so far been fruitless.

Cassese also ordered that the indictment, unsealed Wednesday, be advertised in Lebanon. Advertising the indictment would be a step toward having the suspects tried in absentia in the Netherlands, if they are not arrested.

Cassese added that the Lebanese prosecutor general must now file monthly reports to the Special Tribunal for Lebanon on efforts to arrest the suspects.

Hariri was killed by a suicide truck bomb on Feb. 14, 2005, in one of the most dramatic political assassinations in the Middle East. A billionaire businessman, Hariri was Lebanon's most prominent politician after the 15-year civil war ended in 1990.

Hezbollah, which supports the present Lebanese government, has denounced the tribunal and refused to hand over suspects.

Cassese's call for more help will likely establish whether the government is prepared to confront Hezbollah, the country's most heavily armed force, in an attempt to arrest the men.

The indictment unveiled Wednesday relies heavily on circumstantial evidence such as telephone records to link the suspects to the assassination, reinforcing Hezbollah's criticism of the court.

"The text in our hands now is based on analysis and not clear evidence," Hezbollah leader Sheik Hassan Nasrallah said in a speech. "Those who were indicted should not be called charged but unjustly treated."

The indictment alleges the plot's mastermind is Mustafa Badreddine, a Hezbollah commander and the suspected bomb maker who blew up the U.S. Marine barracks in Beirut in 1983, killing 241 Americans.

The other suspects are Salim Ayyash, also known as Abu Salim; Assad Sabra; and Hassan Oneissi, who changed his name to Hassan Issa.

Prosecutors alleged Ayyash led the assassination team and the two other suspects were responsible for a false claim of responsibility intended to throw investigators off track.