The Vatican's envoy to Syria Mario Zenari blamed both sides for violations in the conflict raging in Syria and called for humanitarian law to be respected in an interview aired on Wednesday.
"We have to demand that all sides in the conflict rigorously respect international humanitarian law which as we can see has fallen apart due to the fault of both warring sides," Zenari told Vatican radio.
The priority "is to demand that the limits already determined under international humanitarian law be respected," he said.
"We are speechless, it is difficult to comment. We are shocked and profoundly pained and worried for the future," he added.
Zenari said that Christians in Syria should act as "bridge builders."
Around 7.5 percent of Syria's 20 million inhabitants are Christian.
Many Christians are concerned about an Iraq-style scenario in which they could come under threat if the regime of President Bashar al-Assad collapses.