A billboard of assassinated Lebanese prime minister Rafiq Hariri sits outside his burial site in downtown Beirut. (Janine Zacharia/Washington Post)

A U.N.-mandated court charged with investigating the 2005 assassination of former Lebanese prime minister Rafiq al-Hariri named four members of the Shiite group Hezbollah as the perpetrators, according to an indictment released Wednesday that raised as many questions as it answered about the killing, which polarized Lebanon.

The broad outlines of the charges and the identities of the suspects had been leaked to the media over the past year, and the allegation that Hezbollah, now the dominant force in Lebanon’s government, might have been involved in the killing came as no surprise.

But the document details for the first time the mostly circumstantial evidence that the Special Tribunal for Lebanon has unearthed during the six-year investigation, in which suspicions initially focused on the Syrian government as the chief architect of the attack and later shifted to those who carried out the massive truck bombing on Beirut’s seafront.

Among those named is Mustafa Badreddine, a Hezbollah commander who was imprisoned for his role in bombings against the U.S. and French embassies in Kuwait in 1983 and who is a brother-in-law of Imad Mughniyah, a Hezbollah figure implicated in numerous attacks against U.S. interests before he was assassinated in Damascus in 2008.

Those attacks include the 1985 hijacking of a TWA flight and a string of kidnappings of U.S. citizens in Beirut, whose abductors’ chief demand was Badreddine’s release. He was freed when prisoners were let go during Saddam Hussein’s invasion of Kuwait in 1990.

The others named are Salim Jamil Ayyash, who was also related to Mughniyah by marriage, Hussein Hassan Oneissi and Assad Hassan Sabra, all of whom were Hezbollah supporters, the indictment says.

The indictment acknowledges that the evidence against the four is circumstantial, based on an analysis of cellphone records that allegedly demonstrate that they possessed cellphones that were used to plan, coordinate and execute the Hariri bombing.

In a televised address, Hezbollah’s leader, Hasan Nasrallah, denounced the cellphone analysis as “ridiculous” and said the recent arrests of numerous Israeli spy suspects working for Lebanon’s telecommunications networks tainted any such evidence.

The indictment “doesn’t prove that any of these suspects made any of these calls or even owned these phones,” he said. “We have proven beyond a doubt the huge extent to which Israel has penetrated the telecoms network.”

Hariri’s son, Saad Hariri, who inherited the leadership of his father’s mostly Sunni Future Movement, said the indictment brought Lebanon closer to uncovering the truth about who was responsible and urged the Hezbollah-led government to cooperate with the tribunal and hand over the suspects. “The sun of truth and justice has started shining on Lebanon,” he said in a statement. “Nothing will be able to disable this new dawn, no matter the intimidation and the threats.”

Lebanon’s government has said that it will not cooperate or turn in the suspects, leaving in doubt whether the tribunal, an unprecedented effort to bring accountability to a country with a history of unsolved bombings and assassinations, will achieve its stated goal of bringing to justice those responsible for the slaying.

Established at the urging of the George W. Bush administration, the tribunal was also widely regarded in Lebanon and beyond as a means of undermining the Syrian government, which many Lebanese initially blamed for the killing.

The assassination triggered a popular uprising dominated by the country’s Christian, Sunni and Druze sects that polarized Lebanon along sectarian lines, forced the end of Syria’s three-decade occupation and heralded the election of a pro-Western government.

But Hezbollah has since wrested control of the government from its rivals and Syria is not mentioned in the indictment, which also does not attempt to explain why Hezbollah operatives set out to kill Hariri or on whose orders they were acting.

Though the question of who killed Hariri remains divisive, the indictment, with all of its ambiguities, seems unlikely to significantly shift opinion in the country, analysts said.

“There will be a bit more raising of tensions, but I don’t think it’s a game changer, because the country has been divided for years now over this issue,” said Paul Salem, director of the Carnegie Middle East Center in Beirut.