has witnessed several attacks on foreigners in recent months as its overall security has deteriorated amid a growing al Qaeda and Taliban-led insurgency. In early February, in the southwestern city of Quetta, purportedly by separatists.
The seven-minute video appears to show the Polish hostage, Piotr Stanczak, sitting on the floor flanked by two masked men. Off camera, a militant briefly engages him in conversation before three others behead him. One of the hooded men then addresses the camera, blaming Pakistan for the killing for not agreeing to their demands to release Taliban prisoners.
If confirmed, Stanczak's death would apparently be the first killing of a Western hostage in Pakistan since U.S. journalist Daniel Pearl was beheaded in 2002.
The video was given to an Associated Press reporter Sunday in northwestern Pakistan on a flash drive by an intermediary who said he obtained it from the Taliban. The AP has elected not to distribute the images. Other international media also reported receiving or viewing footage of the killing.
Polish security services minister Jacek Cichocki said that in his opinion "that is the Pole and the film is authentic," adding final confirmation would have to wait until diplomatic and consular services receive the body.
Stanczak was surveying oil and gas fields for Geofizyka Krakow, a Polish geophysics institute.
"We believed the whole time, even up to the last minute, that the kidnapping affair would end well. Now, we know that's not the case," Leopold Sulkowski, president of the institute, told reporters in Krakow, Poland.
"At this sad and tragic moment, we can't find clear or strong enough words to condemn the monstrous and criminal act."
Pakistani Interior Ministry spokesman Shahidullah Baig said Sunday the government was investigating the existence of the video. He did not immediately respond to requests for comment Monday.
Violence in Pakistan and Afghanistan has soared since U.S.-led forces ousted the Taliban regime in Afghanistan in 2001. Many militants fled across the border to Pakistan, establishing bases and continuing to attack U.S. and NATO forces in Afghanistan.
President Barack Obama has made resolving the Afghan war a key focus of his foreign policy strategy, appointing heavyweight diplomat Richard Holbrooke as a special representative to Pakistan and Afghanistan.
Holbrooke, who was the White House envoy to the Balkans in the Kosovo conflict, was due to visit Pakistan from Monday to Thursday, according to the Pakistani Foreign Ministry. At a security conference in Germany over the weekend, Holbrooke described the Afghan campaign as "one theater of war straddling an ill-defined border."
"We have to think of it that way and not distinguish between the two," he said.
But Holbrooke will face considerable challenges in his new assignment. A European ambassador based in Islamabad, speaking to CBS News ahead of his arrival compared the Pakistan-Afghanistan situation with Holbrooke's previous assignment: "Bosnia was like freshman or sophomore. By comparison this would be a tough graduate assignment which would be far from easy."
Pakistani nationalists have seized the opportunity of Holbrooke's visit to revive calls for a tougher approach towards the U.S., reports CBS News' Farhan Bokhari.
"We have to tell the U.S. in clear terms we can't offer more sacrifices. We have lost our soldiers and many of our innocent people have been killed for a cause, which is a U.S. cause," said Khurshid Ahmed, a leader of the Jamaat-i-Islami, Pakistan's largest Islamic political party, in an interview with CBS News. "There has to be a limit to how far we can sacrifice our own interests, and fight for a cause which is dividing our own country."
The U.S. Embassy said Monday morning that Holbrooke was not yet in Pakistan, declining to reveal exactly when he would arrive.
A spokesman for the Taliban in northwest Pakistan's Darra Adam Khel area said Saturday that they killed the Polish captive because the government missed a deadline to release 26 prisoners. Armed men pulled Stanczak from his car on Sept. 28 after killing three Pakistanis traveling with him near the city of Attock in northwestern Pakistan.
Also Monday, at least 14 people died and six others were wounded when mortar shells hit a house twice in the Darra Adam Khel area, a local government official said on condition of anonymity because he was not authorized to speak to the media.
It was unclear who fired the shells, but the second landed as people gathered to help those struck by the first.
Darra Adam Khel lies just outside the semiautonomous tribal regions, where al Qaeda and Taliban militants have long had strongholds.