Kidnappers freed two Syrian bishops on Tuesday, April 23 who had been abducted in the northern city of Aleppo, a church official said, but the identities of their kidnappers remained uncertain, Reuters reported.

"The two are on their way to the patriarchy in Aleppo," Bishop Tony Yazigi said.

Yazigi, a relative of one of the kidnapped bishops, did not say who was behind the kidnapping of Greek Orthodox archbishop Paul Yazigi and Syriac Orthodox archbishop Yohanna Ibrahim.

They were seized on Monday near the commercial and industrial hub of Aleppo, which is contested by rebels and forces loyal to President Bashar al-Assad.

The authorities blamed rebels for the incident but Western-backed Syrian opposition fighters in the province denied they had kidnapped the two and said they were working for their release and trying to find out who had taken them.

The bishops were the most senior church figures caught up in the fight between Assad's forces and opposition fighters trying to end four decades of family rule by Assad and his late father.

The conflict has killed more than 70,000 people and frightened minority groups as the mainly Sunni Muslim rebels gain ground in northern Syria, where Salafist and Jihadist groups, including al Qaeda linked al-Nusra Front, have emerged as among the most formidable formations fighting Assad's forces.

The two bishops' churches - the Greek Orthodox and Syriac Orthodox Churches "of Antioch and All the East" - are both based in Damascus, with followers across the Middle East, part of a worldwide family of Orthodox churches.