Some 52 Assyrian Christian families who were abducted by jihadists from the group calling itself Islamic State have been released without having to pay any ransom, a high-ranking church official has said.

Citing sources working in the area, the Apostolic Nuncio to Syria Monsignor Mario Zenari said the families had been released between March 5 and 6, the Assyrian International News Agency reported March 10.

"The 52 families who were held for days by the jihadists are now safe," Zenari said in an interview. "The militia still holds 16 people. Half of them are Christians; the other half is made up of Kurds."

Zenari suspected that the families had been taken away to serve as a "human shield" as the jihadists sought cover from the bombing raids mounted by the international coalition.

In the interview, the prelate described the situation in the strife-torn country as "bad."

"Yesterday was a tough day both in Damascus and Aleppo," he said.

"We could hear planes over our heads, and various rounds of mortar landed in various parts of the capital," Zenari continued. "The next days are not going to be any better."

Clashes are still breaking out different parts of Syria as violence between rebel groups and security forces loyal to Syrian President Bashar al Assad continue to erupt.

Last week, United Nations envoy Staffan De Mistura attempted to broker a truce between the groups, proposing a temporary ceasefire in Aleppo to allow humanitarian aid to reach those caught in the crossfire.

The lull would have been an opportune time for international mediators to broker a political agreement among the warring groups.

But representatives from both the rebels and the Islamist fighters declined the truce.

Zenari said he feared that the talks spearheaded by the United Nations would fail. With no signs of letup as far as the conflict is concerned, the prelate said he is anticipating for the worst.

"Our fear was that talks would fail," said the apostolic nuncio. "Now we have to wait and see what happens, but there is little room for optimism."

Since the uprising against yhe regime of Syrian President Bashar al Assad began in 2011, more than 3.2 million people have fled the country whilst another 7.6 million are internally displaced.

At least 200,000 people have been killed in the fighting, many of them civilians, the Assyrian International News Agency reported.

Early in 2013, IS showed itself using violence and brutality seizing large swathes of Syrian and Iraqi territory, where it imposed a reign of terror.