Just hours after the Turkish Foreign Ministry spokesman reaffirmed that no formal orders had been drawn to approve invading northern Iraq, reports are emerging that thousands of Turkish troops are already conducting operations across the border.

Further, AP reports that the Turkish military has asked for, though not yet received, authorization for more extensive operations.

Several thousand Turkish troops crossed into northern Iraq early Wednesday to chase Kurdish guerrillas who operate from bases there, two "senior security officials" told the AP.

"It is not a major offensive and the number of troops is not in the tens of thousands," one of the officials, based in southeast Turkey, told The Associated Press by telephone. The officials did not say where the Turkish force was operating in northern Iraq, nor did he say how long they would be there.

The officials said any confrontation with Iraqi Kurdish groups, who have warned against a Turkish incursion, could trigger a larger cross-border operation. The Turkish military has asked the government in Ankara to approve such an incursion, but the government has not given formal approval.

Reuters reports that Turkey's military General Staff said on Wednesday it could not confirm a report it had sent several thousand troops into northern Iraq to combat Kurdish militants hiding there.

"I cannot confirm this report," said a General Staff official, referring to the Associated Press report.

Earlier, the DEBKAfile Web site said 50,000 men had been dispatched as the "first wave" of an invading force, but Ankara described the report as "disinformation".

A White House spokesman, in Germany for a G8 summit, said U.S. officials in the region had detected "no new activity" in northern Iraq.

Iraq's Foreign Minister Hoshiyar Zebari said on Wednesday there was no evidence that Turkish troops had crossed the Iraqi border to launch a military operation against Turkish rebels hiding in the mountains.

"We have checked all along the border and there hasn't been any incursion or military operation inside Iraqi territory," he told Reuters.

"Iraq will not tolerate any military incursion. There is always room for dialogue," he said.

Fouad Hussein, the head of the office of Kurdistan President Masoud Barzani, told Reuters, "Up to this moment, there is no incursion by Turkish troops into the Iraq Kurdistan region."

"But I don't know if the troops have entered into distant parts of the mountains, situated between Iraq and Turkey."