Poland's prime minister has ordered an investigation into whether the CIA ran secret jails for terrorist suspects here, saying the issue must be cleared up before it becomes "dangerous" for his country.
Kazimierz Marcinkiewicz made the announcement on Saturday, a day after a military analyst for a prominent rights group insisted Poland was a central CIA detention center.
Poland's army chief on Saturday denied the allegations, while Washington maintained its policy of not confirming the existence of any prisons.
"I'm not going to get into the right of a sovereign country to conduct an investigation on its own territory," said Frederick Jones, spokesman for the White House's National Security Council. "That's their right."
Marcinkiewicz said he was "commissioning a detailed check in all places possible, to precisely check if there is any proof that such an event took place in our country."
"It is necessary to finally close the issue because it could be dangerous to Poland," he said in comments aired by Poland's TVN24.
Marcinkiewicz didn't elaborate, and his spokesman, Konrad Ciesiolkiewicz, said he had no details of how the government would look into the allegations or how long it would take.
More than a half-dozen investigations are under way into whether European countries may have hosted secret US-run prisons in which prisoners were tortured, and whether European airports and airspace were used for alleged CIA flights transporting prisoners to countries where torture is practiced.
Polish officials have consistently denied the existence of such jails.
"Polish authorities have unambiguously responded to this question," General Czeslaw Piatas, the Polish army's chief of staff, said on Saturday in Budapest after meeting with his Central European counterparts.
"I would like to once again recall what President Aleksander Kwasniewski has said, that there has not been that kind of captivity in Poland," Piatas said.
However, Marc Garlasco, a senior military analyst for the New York-based Human Rights Watch, said in remarks published on Friday that Poland was the chief CIA detention site in Europe, part of a system of clandestine prisons for interrogating al-Qaeda suspects.
"Poland was the main base of interrogating prisoners, and Romania was more of a hub," Garlasco was quoted as saying in Polish newspaper Gazeta Wyborcza.
"This is what our sources from the CIA tell us, and what is shown from the documents we gathered.," he said.'
Reports of clandestine prisons have roiled Europe for a month. US Secretary of State Condoleezza Rice asserted during her recent trip to Europe that the US acts within the law, and argued that Europeans were safer because of tough US tactics.
However, she refused to discuss intelligence operations and address some of the lingering questions about the alleged CIA detention centers.
On Saturday, Gazeta Wyborcza reported that Gulfstream airplanes belonging to either the CIA or the FBI had landed at least five times at the Szczytno-Szymany airport in northeastern Poland since December 2002.
Reports last month that a CIA Boeing 737 landed at the same airport on Sept. 22, 2003, launched much of the speculation of how Poland might have cooperated with the CIA.
Quoting unidentified former airport employees, the paper said Saturday that the planes remained on the runway and did not refuel. Only border control officials and mini vans approached the aircraft.



