Two bishops of Aleppo abducted in 2013 in Syria are still alive, according to the Syriac Orthodox Bishop of Beirut, Daniel Kourie.

Kourie was speaking at the ceremony marking the 47th anniversary of the Virgin Mary's apparitions over the dome of the Cathedral of Saints Peter and Paul in Moussaitbeh, near Beirut, the Assyrian International News Agency (AINA) reported.

The commemoration, which comes on the first Sunday after Easter Day, coincided this year with the fourth anniversary of the abductions in Syria, on 22 April 2013, of the Syriac Orthodox and Greek Orthodox bishops of Aleppo, Youhanna Ibrahim and Boulos Yazigi, whose fates remain unknown.

Portraits of the two Bishops were displayed inside the cathedral and carried during the candle-lit procession that marked the anniversary of the apparitions.

As far as Kourie knew, he said, 'the two bishops are still alive [and] those who believe otherwise must give us evidence for their claim'.

Kourie called on the Lebanese authorities to make this case a national cause given its impact on interfaith coexistence and dialogue, according to AINA.

He also attacked 'religious and ethnic cleansing in Syria, Iraq and Egypt' and the states that support it.

The abducted Bishops were the most senior church officials to be targeted during Syria's bloody civil war, and they have not been heard of since they were reportedly taken at gunpoint.

The two men were seized as they returned from a humanitarian mission in neighbouring Turkey. Their driver, who was a deacon, was shot and killed in the attack.

Athens set up a crisis management team, sent an emissary to the Middle East, contacted governments across the region and used its considerable contacts with the Syrian opposition in a bid to shed light on the clerics' whereabouts, according to the Guardian.

Greece's prime minister, Antonis Samaras, appealed in 2013 for help to the Istanbul-based ecumenical patriarch, Bartholomew, spiritual leader of the world's Orthodox faithful.