BEIRUT — A UN-backed special tribunal convicted on Tuesday one of four men accused of killing a former Lebanese prime minister in Beirut in 2005.

Salim Ayyash and the others, all from the Shiite militant group Hezbollah, had been on trial in absentia since 2014.

The killing of Rafik Hariri, one of Lebanon's most prominent politicians, caused outrage across the country.

Ayyash was found guilty of conspiracy to commit a terrorist act, murdering Hariri, murdering 21 others and attempting to murder 226 more in the suicide car bombing on Feb. 14, 2005.

The judges said evidence showed Ayyash had possessed one of six mobile phones used by the team which assassinated Hariri.

The billionaire businessman and politician's killing was a watershed moment for Lebanon and gave rise to rival alliances that shaped Lebanese politics for years afterward.

Alongside Ayyash, the three other defendants — Hussein Hassan Oneissi, Assad Hassan Sabra and Hassan Habib Merhi — were acquitted by the Special Tribunal for Lebanon (STL), based on the outskirts of The Hague in The Netherlands.

A fifth man — Mustafa Badreddine, the commander of Hezbollah's military wing — was dropped from the indictment after he was killed in Syria in 2016. Prosecutors had described him as an "overall controller of the operation" to assassinate Hariri, according to BBC.

The presiding judge, David Re, also said there was no direct evidence implicating Hezbollah's leadership or one of its patron's, Syria, in the attack.

Hezbollah had consistently denied any involvement and none of the men — whose whereabouts are unknown - have come forward.

The long-awaited verdict comes at a particularly precarious time for Lebanon.

It was delayed by the devastating blast at Beirut port two weeks ago, which led to the resignation of the government, already embattled by months of protest over the collapsing currency and high unemployment.

Hariri's son Saad, who is himself a former prime minister, said in a series of tweets that he accepted the verdict, but that he had expected more information to emerge from the trial.

“We accept the court’s ruling and we want justice to be done so that the criminals are given punishment and they are made to serve it,” Saad Hariri said in a tweet.

“We have been waiting for this moment for 15 years, and this moment reminds us that no matter what happens, we remain one family,” the ex-PM said in another tweet.

Saad Hariri also said: “The Lebanese will no longer accept that their country is a hotbed for killers or a refuge to escape punishment,” — Agencies