Berlin (AFP) - German Chancellor Angela Merkel Monday backed a call from Turkey for a no-fly zone over parts of Syria, saying it would alleviate the situation of displaced Syrians.

"In the current situation it would be helpful, if there could be such an area, where none of the parties are allowed to launch aerial attacks, that is to say, a kind of no-fly zone," she told the daily Stuttgarter Zeitung, when asked about opening up such areas to host people fleeing fighting in the war-torn country.

She acknowledged that it was impossible to negotiate with "terrorists from the Islamic State", "but if it's possible for the anti-Assad coalition and the Assad-supporters to come to an agreement, that would be helpful."

Turkey, which is already hosting around 2.2 million Syrian refugees, has been calling for a secure zone within Syria where the displaced could find refuge.

Top diplomats from world powers agreed at talks in Munich last Friday on a "nationwide cessation of hostilities" within a week, in the latest bid to find an end to Syria's five-year conflict.

But doubts are growing over whether the deal can be honoured, as Turkey has defied international calls and shelled parts of northern Syria for a third day on Monday, while a suspected Russian air strike killed nine people at a hospital supported by Doctors Without Borders in the north-western part of the country.