Updated

The Taliban released a video over the weekend that purports to show the execution of 15 Pakistani soldiers -- punishment, they say, for Pakistan attacks on the militants.

The video, according to AFP, which it says obtained a copy, shows the soldiers lined up in three rows, each with their hands bound behind their back and blindfolded. A Taliban leader criticizes the Pakistani government for killing 12 militants, and warns of more revenge killings if the attacks continue, AFP reports.

Then he opens fire, along with the other Taliban.

Pakistani officials told AFP that the soldiers were killed in the tribal areas that have long been a sanctuary for the Taliban. They had been kidnapped last month in a raid on a checkpoint in northwestern Pakistan and were found dead earlier this month.

The soldier killings and the newly-released video come at a time of tense relations between the U.S. and Pakistan, as the two countries wrestle with how to respond to the continued threat from the Taliban and Al Qaeda.

U.S. drone strikes in Pakistan have become increasingly unpopular, especially after the mistaken identity attacks in November that killed 24 Pakistani soldiers. But U.S. officials long have struggled to get Pakistan to mobilize against the militant threat.

On Monday, Pakistan's army formally rejected a U.S. claim that the strikes were justified as self-defense, the Associated Press reports.

In a detailed report, the army said that Pakistani troops did not trigger the Nov. 26 incident at two posts along the Afghan border by firing at American and Afghan forces, as the U.S. has alleged. Pakistan's army said its troops shot at suspected militants who were nowhere near coalition troops.

"Trying to affix partial responsibility of the incident on Pakistan is, therefore, unjustified and unacceptable," said the report, which was issued in response to the U.S. investigation that concluded at the end of December.

The U.S. expressed condolences for the deaths of the Pakistani soldiers but said American troops acted "with appropriate force" in self-defense because they thought they were being attacked by Taliban insurgents.

A senior Pakistan official told Fox News last week that the country was prepared to invite U.S. military trainers back into the country later this year, but drone strikes would be prohibited. That news came on the heels of reports that the most recent U.S. strikes had killed a top Al Qaeda operative.

The Associated Press contributed to this report.