U.N. chief voices concern about fighting in northwest Syria, calls for ceasefire

United Nations Secretary-General Antonio Guterres on Thursday voiced "grave concern" about the escalation of fighting in northwest Syria and reiterated his call for a ceasefire.

"The Secretary-General is following with grave concern the escalation in northwest Syria and reports that dozens of Turkish soldiers have been killed by an airstrike," U.N. spokesman Stephane Dujarric said in a statement.

"The Secretary-General reiterates his call for an immediate ceasefire and expresses particular concern about the risk to civilians from escalating military actions. Without urgent action, the risk of even greater escalation grows by the hour."