Turkish Kurd militants threatened on Thursday, March 22 to turn all Kurdish populated areas into a "war zone" if Turkish troops entered Syria, a sign the Kurdistan Workers Party (PKK) which has allies in Syria may be taking sides in the conflict there, Reuters reported.

A renewed alliance between Damascus and the PKK would anger Turkey and could prompt it to take an even stronger line against Syrian President Bashar al-Assad over his brutal repression of anti-government protesters.

PKK field commander Murat Karayilan said Turkey was preparing the ground for an intervention in Syria.

Western Kurdistan is the term Kurdish nationalists use to describe Kurdish areas of northeast Syria, while by Kurdistan they mean the Kurdish areas of Turkey, Iraq, Syria and Iran.

Turkish Prime Minister Tayyip Erdogan said last week that setting up a "safe zone" or a "buffer zone" along the border with Syria to protect civilians from Assad's forces was among the options being considered should the stream of refugees turn into a flood.

Setting up such a zone would involve troops entering Syria to secure territory. Turkey has turned sharply against its former friend Assad and has taken a lead in trying to forge international agreement on the need for stronger action on Syria.

While Syrian government forces are clashing daily with insurgents demanding the downfall of Assad, Syrian Kurdish areas have remained relatively calm, despite many Kurds' long-standing opposition to the government.

Some Syrian Kurdish groups opposed to Assad have formed their own umbrella group after complaining of being sidelined by the main opposition Syrian National Council (SNC), which they say is dominated by Arab nationalists.

But the comparative calm in Syria's Kurdish northeast may also be related to what some Kurdish analysts say is the growing influence of the Democratic Union Party (PYD), a Syrian Kurdish group allied to the PKK which has kept away from the opposition.