Updated

Poland pledges to capture and "punish" the Taliban militants who beheaded a Polish engineer in Pakistan on Friday before delivering a video of the attack to the media, the Times of London reports.

Piotr Stanczak was reportedly kidnapped four months ago while working in the Attock district — a region close to Pakistan's lawless North West Frontier Province.

A video released to media outlets Sunday shows the beheading of Stanczak just minutes after he appears on tape urging the Polish government not to send troops to neighboring Afghanistan.

On Monday, Poland's Foreign Minister Radoslaw Sikorski said the video had been authenticated and pledged to bring the terrorists to justice, according to the Times of London.

"The cassette of the execution, this bestial execution, is authentic and unfortunately it confirms the worst," Sikorski reportedly said in a statement. "Now we can no longer save our compatriot, we are going to try to punish his killers."

Sikorski promised to issue international arrest warrants for the Taliban militants, and officials charged that elements within the Pakistani government shared blame for the killing.

But Pakistan's top diplomat in Poland firmly rejected the accusation that some members of the Islamabad government are sympathetic to Islamic extremists, saying his country is snarled in a bitter fight with terrorist groups that is killing many of its own.

Stanczak's death would appear to be the first killing of a Western hostage in Pakistan since U.S. journalist Daniel Pearl was beheaded in 2002.

The seven-minute video shows 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 by not agreeing to their demands to release Taliban prisoners.

The militants issued a statement on the video warning that other foreign hostages would be executed if the Pakistani government did not release some 60 detainees held by the military, the Times of London reported.

The insurgents are reportedly holding at least four foreigners — including a Chinese engineer and Afghan and Iranian diplomats.

Pakistani Interior Ministry spokesman Shahidullah Baig said Sunday that 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.

The news of Stanczak's execution came just a day before U.S. Special Representative for Afghanistan and Pakistan Ambassador Richard Holbrooke arrived in Islamabad for scheduled meetings with senior Pakistani government officials.

The Associated Press contributed to this report.

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