Argentina on Thursday sought an international arrest warrant for four Lebanese citizens suspected of involvement in the 1994 bomb attack on the AMIA Jewish community centre in Buenos Aires that killed 85 people and injured 300.
A judge granted a prosecutor's request to seek a warrant from Interpol based on reasonable suspicion that the four were "employees or operational agents" of Hezbollah.
The four are Hussein Mounir Mouzannar, Ali Hussein Abdallah, Farouk Abdul Hay Omairi and Abdallah Salman (aka 'El Reda').
They are thought to reside in either Paraguay, Brazil or Beirut.
'El Reda' is suspected of "the coordination of the arrival and departure of the operational group" that carried out the attack, according to court documents.
The attack on the AMIA Jewish community centre in the capital was the worst in the country's history and came just two years after a bombing at the Israeli Embassy killed 29 and wounded 200.
The 1994 attack has never been claimed or solved, but Argentina and Israel suspect Lebanon's Shiite Hezbollah group carried it out at Iran's request.
Tehran denies any involvement.
Arrest warrants have been pending against eight Iranians since 2006.
Argentina is home to Latin America's largest Jewish community. It also is home to immigrant communities from the Middle East – from Syria and Lebanon in particular.
Vice-President Cristina Fernández de Kirchner had been investigated for allegedly colluding with Iran to obstruct the investigation into the bombing when she was head of state from 2007 to 2015. The case against her was later dropped.