THEY are terrorists, yes. But like those from another age.

The PKK, or Kurdistan Workers’ Party, has little in common with the Islamist violence which has dominated world headlines since those Al Qaeda planes hit the Twin Towers of New York in 2001.

This is an old-style secular guerrilla group waging an armed struggle against the Turkish state for a Kurdish homeland. It has more in common with the pre-Good Friday IRA or Basque separatists ETA than with so-called Islamic State. Its victims, of course, are just as dead as those killed by ISIS. They include a Turkish police officer and a court worker who died at their hands in Izmir this week. Last year a PKK offshoot was behind the twin bombing of a football stadium in Istanbul which cost 38 lives.

Yet it is worth drawing the distinction between old school leftists and Islamist zealots. Why? Because, as we report today, Police Scotland is investigating allegations of PKK fundraising in Edinburgh. And, whatever the outcome of this case, I suspect people would have reason to be more alarmed if it involved Islamic State rather than the PKK

It is now up to prosecutors to decide whether to make criminal charges against suspects and, if they do, courts will decide their guilt or innocence. The individuals concerned, a police briefing shows, are also suspected of fraud, trading standards, tax and immigration offences. Detective Chief Superintendent Gerry McLean, head of the unit dealing with terrorism and organised crime, said what Edinburgh citizens would want to hear: “I would like to reassure the public that there was no danger to them.”

Originally Marxist when it was set up in the 1970s, the group has been in an on-off military struggle with Turks since the 1980s. Perhaps 40,000 people have died in a “dirty war” between Turkey and Kurdish fighters, which peaked some two decades ago.

A two-year ceasefire ended in mid-2015. Turkey’s increasingly hardline government has cracked down on Kurds – a stateless, ethnic group spread across the Middle East – since surviving a coup attempt last summer. The PKK says it is not seeking full independence for an ill-defined region inside Turkey but the Turks insist the group is separatist.

There is a sizeable group of Turkish Kurds in Scotland, many arriving as refugees, formally or informally, during the “dirty war” of the 1980s and 1990s. They organised protests against Turkey last year and have won political support too. A year ago SNP MEP Alyn Smith added his voice to calls for the PKK to be removed from a list of proscribed organisations.

The prominent nationalist thought such a move would force Turkey, now on the frontline of the fight with Islamic State, back to the negotiating table with the Kurds. He said: “There’s been a history of treatment of the Kurdish people which does not reflect well on Turkey’s status as a democratic country. We’ve seen attacks on civilians attacks on journalists attacks on trade unions.”

Scotland’s Kurdish community also includes people from Iraq and Syria, where Kurds are fighting Islamic State, and Iran. John MacDonald of think tank Scottish Global Forum, said tensions between Turks and Kurds would likely continue to fuel violence.

He said: “Few would deny there is much to nourish anger and resentment among Kurds in Turkey and beyond.”