A Turkish-backed Free Syrian Army fighter holds a weapon as he walks north of Afrin, Syria March 17, 2018. REUTERS/Khalil Ashawi

ISTANBUL (Reuters) - The Turkish military denied on Saturday that it had struck a hospital in Syria’s Afrin region, where it is waging a nearly two-month-old offensive against Kurdish YPG forces.

The YPG and Syrian Observatory for Human Rights monitor said a Turkish air strike hit Afrin town’s main hospital on Friday night, killing 16 people.

“Reports that Turkish armed forces bombed a hospital in Afrin are false,” the military said on Twitter, adding that it was carrying out the campaign in a way that would not hurt civilians.

Since launching its ground offensive inside Syria’s Afrin region in January, it has driven YPG forces back from the Turkish border and advanced on the western and eastern flanks of the town of Afrin itself.

A spokeswoman for the U.N. human rights office said it had had “deeply alarming reports” of civilians killed and wounded in Afrin, and of the Kurds preventing civilians from leaving.

About 11,000 people, many of them Kurdish migrants, marched in the northern German city of Hanover on Saturday to protest the Turkish military operation in Afrin.

Local police said the demonstration, scheduled to mark the Kurdish New Year, was largely peaceful although they confiscated banned flags and signs linked to the banned Kurdistan Workers Party (PKK). Two people were detained, police said.