LONDON (Reuters) - Any Turkish attack on northern Iraq could further increase the number of people fleeing their homes and cut off one of the few remaining ways out for refugees desperate to leave Iraq, aid workers say.
After a string of attacks on Turkish troops, Ankara has threatened military action in northern Iraq unless Iraqi and U.S. forces crack down on separatist Kurdish guerrillas.
Aid workers say several hundred people fled border villages after shelling last week. Northern Iraq is already home to more than 800,000 displaced people, according to the office of the United Nations High Commissioner for Refugees.
"If military action does take place, then one of the few safe havens for Iraqis may not be there any more," said UNHCR spokeswoman Astrid van Genderen Stort.
Despite occasional bombings, Iraqi Kurdistan has largely been spared the sectarian violence that has raged elsewhere in the country.
Some 160,000 Iraqis from the main Shia and Sunni groups have fled there to seek safety among the Kurds, prompting Kurdish officials to tighten restrictions on new arrivals.
Any new fighting in the north could push both these new arrivals and Kurds back south towards existing violence.
"Turkish attacks would have the potential to create more displacement," International Organisation for Migration (IOM) Iraq displacement specialist Dana Graber Ladek told Reuters.
"We are planning to set up hubs with relief items in the event there is displacement. As far as we know, the Kurdish authorities are not planning on setting up camps but they have put the hospitals on alert."
Aid workers say some 4.2 million Iraqis have fled their homes since the U.S.-led invasion in one of the world's largest, fastest-growing refugee crises. Roughly half remain within Iraq while half have fled the country, most to Syria and Jordan.
Both countries have now tightened visa restrictions and made it much harder for Iraqis to enter. Turkey is also seen as unwelcoming, but some refugees have slipped across the same porous border that allows Kurdish rebels across.
Few register there, many passing straight through on the way to friendlier countries such as Sweden, with its generous welfare and more accepting immigration system.
"If there is more hostility between Iraq and Turkey, it is less likely people will be able to move across the border and they will have to find alternatives -- if they can," said IOM's Graber Ladek. "But it is becoming difficult."