In an interview with broadcaster AHaber, Canikli said Turkey was developing weapons systems against anti-tank missiles used by the Syrian Kurdish YPG. Also Turkey’s operation in Syria’s Kurdish-controlled Afrin region has started with cross-border shelling, but no troops have gone into Afrin, Turkish Defence Minister Nurettin Canikli said on Friday.

The Syrian Kurdish YPG militia said Turkish forces had fired around 70 shells at Kurdish villages in the Afrin region of northwestern Syria in a bombardment from Turkish territory that began around midnight and continued into Friday morning.

Rojhat Roj, a YPG spokesman in Afrin, told Reuters it marked the heaviest Turkish bombardment since the Turkish government stepped up threats to take military action against the Kurdish region. Roj, speaking from Afrin, said the YPG would respond with utmost force to any attack on Afrin.

It comes after thousands of protesters demonstrated in Kurdish-held parts of northern Syria on Thursday after Turkish threats to launch an offensive on the region.

In a series of statements since Sunday, President Recep Tayyip Erdogan has threatened to launch an operation against towns in Syria controlled by the People’s Protection Units (YPG) militia, calling the areas “nests” of terror.

Syria’s Kurdish minority, estimated at 15 percent of the population, have long been oppressed by Damascus.

The YPG, which is linked to Turkey’s outlawed Kurdistan Workers Party (PKK), has taken advantage of years of war to carve out a de facto autonomous region in Syria’s north and northeast, notably the region of Afrin.

Turkey fears that could stir similar ambitions among its own substantial Kurdish population.

A Turkish army tank moves toward the Syrian border, in Reyhan

A Turkish army tank moves toward the Syrian border, in Reyhan (AAP) AAP

Several thousand people demonstrated against Erdogan on Thursday in Jawadiyeh, in the northeastern province of Hasakeh, an AFP correspondent said.

“We are united and we want to support our people in Afrin,” said Abdallah Khaled, a 40-year-old protester.

Protestors shouted “Down, down, Erdogan!” and “With our soul, with our blood, we are with you Afrin!”

Some waved Kurdish and YPG flags while others carried portraits of Abdullah Ocalan, imprisoned leader of the PKK.

Signs in Arabic and Kurdish read: “We condemn attack by the Turkish state against our people in Afrin.”

People's Protection Units or YPG protestors waving a giant poster of jailed PKK leader Abdullah Ocalan

People’s Protection Units or YPG protestors waving a giant poster of jailed PKK leader Abdullah Ocalan AAP

Several other parts of Kurdish-controlled territories saw similar gatherings, notably Afrin itself, where organisers said tens of thousands of people took to the streets despite the rain.

On Sunday, the US-led coalition fighting the Islamic State group in Syria announced that it was training local fighters, including Kurdish militia, as a “border security force”.

That prompted an outcry from Ankara.

In a televised speech Monday, Erdogan threatened that “tomorrow, the day after, within a short period, we will get rid of terror nests one-by-one in Syria starting with Afrin and Manbij,” also in northern Syria.

The United States insisted Wednesday it does not intend to create an “army” or conventional border guards.

Damascus said Thursday that Syria’s air force could destroy any Turkish warplanes used over its territory.