KABUL, Afghanistan – The Afghan government today blamed U.S.-led coalition forces for the killing of Kandahar’s police chief and criminal investigations director on coalition forces, saying the Afghan guards who shot them to death were working for and trained by the coalition.

U.S. officials in Washington, who spoke only on the condition of anonymity because classified matters are involved, told McClatchy that American intelligence agencies are investigating whether some of the guards may have been among the Afghans whom the CIA has recruited, trained and paid to help fight the Taliban, al-Qaida and drug trafficking.

Coalition officials in Afghanistan said only that no U.S. or coalition forces were involved in the killings, that the guards weren’t acting “on behalf of U.S. or international forces” and the killings in Kandahar, Afghanistan’s second-largest city and the heart of its opium poppy-growing region, were an “Afghan-on-Afghan” incident.

“These men acted on their own,” said Navy Chief Petty Officer Brian Naranjo, a spokesman for the U.S. military in Kabul.

“I have nothing to add to the other statements made on this incident,” said CIA spokesman George Little.

Afghan President Hamid Karzai condemned the attack, and his younger brother Ahmed Wali Karzai, the head of the Kandahar provincial council, and other officials in Kandahar charged the guards worked for a private security company that had been hired by coalition forces, but offered no specifics.

Today’s incident highlighted the challenge the U.S. and its allies face when Afghan security forces they’re working with or training have their own agendas. The attack also made it clear that when that happens, Afghan officials will hold the coalition responsible, further upsetting the uncertain relationship between the Afghan government and its international allies.

The incident also raises questions about how much the coalition can rely on local forces, some of which have long histories of corruption and abuse, to quell the rising violence in Afghanistan’s most important province and the nation’s major Taliban stronghold, the crux of its security plan here.

The shooting began sometime after 11 a.m., when about a dozen vehicles carrying some 40 Afghan guards pulled up to the prosecutor’s office. The guards, whom Kandahar officials charge work with American Special Forces on counter terrorism raids, accosted the prosecutor, threatened him and demanded the release of a fellow guard named Assadullah, who had been detained for producing counterfeit vehicle documents and plates, said Toryali Weesa, the province’s governor.

The prosecutor refused and called the provincial police chief, Matiullah Qati, who arrived with four police officers who serve as his guards and Abdul Khaliq, the province’s criminal investigations director.

A dispute arose, and the guards began shooting at Qati and Khaliq, according to Ahmed Wali Karzai. The shooting lasted for about 10 minutes, Karzai said, and left Qazi, his four police guards and Khaliq dead. Another six officers were injured. It was unclear whether any of the guards were killed.

Local police arrested at least 41 guards afterward, Weesa said. The governor promised an investigation.

An Afghan soldier guarded the attorney general’s office following a conflict between police and Afghan private security forces in the city of Kandahar province south of Kabul, Afghanistan today. Photo by The Associated Press