Relatives of those killed in Argentina's worst terrorist attack have asked Pope Francis to intervene so that justice is found.

Members of an association of victims of the 1994 bombing of a Jewish community center in Buenos Aires briefly greeted the Argentine pope at the end of his Wednesday general audience.

Their visit came hours ahead a protest in the Argentine capital over the mysterious death of a prosecutor investigating the attack. The prosecutor had alleged that President Cristina Fernandez and her allies shielded Iranian officials accused of masterminding the bombing.

Victim association leader Sergio Burstein told reporters in Rome that Francis said he would to do whatever he could.

Francis, who was auxiliary bishop of Buenos Aires in 1994, has already called for justice for the 85 victims.