Kirkuk, Iraq ? With stunning speed and barely a fight, Kirkuk and its oil fields changed hands Thursday. By sundown, Kurdish fighters roamed unchallenged through the streets, looters had emptied government buildings down to the bathroom fixtures and statues of Saddam Hussein lay broken in the dust.

Kirkuk’s fall — coupled with indications that Mosul, the largest city in the north, might quickly follow — brought the northern front within nearly 60 miles of the Iraqi president’s hometown of Tikrit, the possible last refuge of his rule.

And it left Iraq’s No. 2 oil region almost fully intact. Coalition leaders had feared retreating Iraqi forces might set the fields ablaze, but only one well fire raged near Kirkuk. It was not known if it was caused by fighting or sabotage.

U.S. special operations forces were with the Kurds when they entered the city of 100,000 people, said Maj. Gen. Stanley McChrystal, vice director of the Pentagon’s Joint Staff. They were soon joined by elements of the Army’s 173rd Airborne Brigade.

Secretary of State Colin Powell said he had promised Turkey the Kurds would pull out entirely and be replaced by U.S. troops — easing Turkish fears that the Kurds could use Kirkuk as a step toward an independent state, perhaps inspiring separatists among Kurds in Turkey.

Kirkuk “will be under American control,” White House spokesman Ari Fleischer said.

Jalal Talabani, leader of one of the factions whose forces entered the city, told the Turkish television channel CNN-Turk that all Kurdish fighters would leave by the end of today.

Still, this was an extraordinary day for Iraqi Kurds, a moment akin to the fall of the Iron Curtain. Kurds consider Kirkuk one of the capitals of their ethnic homeland — which has been divided since the 1991 Gulf War, when parts of Kurdish land came under Western protection.

Kirkuk and the northern city of Mosul — Iraq’s third-largest city — were left under Baghdad rule and many Kurds fled to north as Arab settlers moved in.

Early today, U.S.-led troops started moving into Mosul, where military leaders planned to negotiate the city’s surrender.

In Washington, Secretary of Defense Donald Rumsfeld said small numbers of U.S. and Kurdish forces entering Mosul were “being welcomed by the people.”