KIRKUK, Iraq (AP) - Kurds are on the move again in northern Iraq - but this time they're not fleeing. As many as 500 Kurds a day streamed into Kirkuk last month in a land rush that took city officials and U.S. troops by surprise. The influx, which has slowed in September, leaves the nascent city government struggling to cope with dozens of refugee camps on once vacant patches of ground.

Migrants like 60-year-old Tarek Salman Dawoud say they are reclaiming the
ancestral city they were forced to flee under Saddam Hussein's campaigns to
make Kirkuk an Arab city and control its oil wealth.

"This is our land. We've been here for thousands of years," Dawoud said,
standing with other Kurds who shouted in assent. Just behind them, a sea of
dusty canvas tents stretched across a few square miles of a former Iraqi air
base.

However, U.S. officials say the surge is timed to establish residency ahead of
elections slated for January. A strong showing for Kurdish leaders could shift Kirkuk province - which sits atop 6 percent of the world's known oil reserves - into the orbit of the Kurdish autonomous regions to the north.

Arab migrations have shaped this area since oil was discovered here in the
1930s but picked up momentum in the mid-1970s, when Saddam began
asserting control over the government. The New York-based Human Rights
Watch estimates that 250,000 Kurds, Turkmen and Assyrians were expelled
from Kirkuk and other parts of northern Iraq in the 1970s alone.

A 2001 U.N. census in the autonomous Kurdish regions counted more than
800,000 displaced Iraqis.

"Every member of my family was exiled to the north," said Dawoud, who was forced to abandon his Kirkuk home to incoming Arabs in 1995 and move his family to a refugee camp in the autonomous zone. With Saddam and his regime gone, Dawoud and tens of thousands of others
are pouring back.

Already, refugees are building homes in the makeshift camps. Across the city, teams of men could be seen digging foundations on identically sized plots marked on the earth in white chalk and laying concrete blocks or mud bricks.

Many camp residents appear to be part-timers, commuting to their plots on
weekends to build homes and returning to Sulaimaniyah and Irbil to work
during the week, soldiers said.

Officials monitoring the influx estimate some 72,000 refugees, mainly Kurds, have arrived in and around the city in the past 18 months. Smaller numbers of expelled Turkmen and Assyrian Christians have also erected camps in Kirkuk and surrounding villages. Some 50,000 others, mainly Arabs encouraged to migrate here under Saddam, have fled.

About 20,000 Kurds arrived in August alone, encouraged by Kurdish political parties that have given them money or building supplies to help them reclaim their land, said U.S. Army Maj. Mike Davey of the 2nd Brigade of the Hawaii-based 25th Infantry Division, which controls security in Kirkuk.

If they keep coming, this city of 750,000 could have 100,000 new residents
before the first elections since Saddam was ousted last year, officials here say.

The Kurds' return is viewed with alarm by those who fear an independent
Kurdish state, among them Iraqi Arabs and surrounding countries with Kurdish minorities, especially Turkey, said U.S. Army Col. Lloyd Miles, who commands the Kirkuk-based brigade.

"They don't want the Kurds to get control of the oil here," said Miles. "Then they will have a source of income for an independent state."

The migration is putting pressure on Kirkuk's Arabs, some 200,000 mainly poor Shiite Muslims from southern Iraq, who were themselves pushed here by successive Iraqi governments.

Some Arabs have said they are willing to return south if they are given land and homes. Others, who've lived here for a generation, want to stay, Miles said.

Raising the tension, Kurdish politicians in northern Iraq have demanded the
departure of all Arabs who came north during the government's campaign to
make Kirkuk an Arab city. In some cases, Kurdish refugee camps sit just across the road from Arab neighborhoods on the city's south side.

"They want this area back," Davey said of the Kurds. "It's a very visible
presence."

At the same time, Kirkuk is beset by insurgents, mainly Sunni Muslim Arabs, who are pressing the Shiite settlers to stay in the city and refuse to sell their homes, Miles said.

For now, the migration has been peaceful, with only a few incidents of Kurdish intimidation of Arab residents.

But a major demographic shift in this city's precarious four-way ethnic balance could trigger long-term instability, said U.S. Army Maj. Gen. John Batiste, who commands the 1st Infantry Division, which controls the region.

"Kirkuk is the key to avoiding civil war in Iraq," said Lt. Col. Jim Stockmoe, the 1st Infantry's intelligence officer. "Kirkuk is to Iraq what Kosovo is to the
Balkans. That's why it's critical to us and it should be to the Iraqi government."