Afghan Local Police, ALP, listen to a speech during a ceremony presenting new uniforms for ALP at Gizab village of Uruzgan province south west of Kabul, Afghanistan, in this April 24, 2011 file photo. In addition to men wearing Afghan army uniforms, men in police uniforms have killed a number of foreign forces over the years. (Kamran Jebreili/AP)

As fatal attacks on U.S. and NATO troops by their Afghan partners kept up at an alarming rate this year, Afghan officials largely blamed infiltrators they said had been sent by foreign spy agencies. But on Wednesday, the Afghan army acknowledged far wider causes, saying hundreds of its soldiers have been expelled or arrested because of deficient vetting and links to insurgents.

At the same time, Afghanistan’s top military commander said his officers also shared blame for the so-called insider attacks for not giving their men a better understanding of why they should fight against the Taliban alongside their Western allies.

“We neglect, we ignore, we do not know our soldiers. We do not communicate with them. We do not advise and instruct them,” Gen. Sher Mohammad Karimi, the Afghan National Army’s chief of staff, said Wednesday. “They don’t know why we are fighting.”

The Defense Ministry offered no precise numbers or a breakdown of the Afghan troops being held as suspected turncoats vs. those who were dismissed for insufficient documentation and proof of loyalty. Nor did it specify when the actions were taken.

“Hundreds were sacked or detained after showing links with insurgents,” ministry spokesman Zahir Azimi said at a news conference. “In some cases, we had evidence against them; in others, we were simply suspicious.”

At the Pentagon, Lt. Gen. James Terry, deputy commander of U.S. Forces-Afghanistan, said he had heard that 200 or 300 Afghan soldiers were involved but had not confirmed that with Afghan officials. “I am pleased that they are going back and re-vetting,” he said. “The number is, I think, an indication of the seriousness of the Afghan national security forces.”

The announcement came after NATO and Washington stepped up pressure on the Afghan government to curb the escalating number of insider attacks. This year, the strikes — also known as “green-on-blue” attacks — have killed at least 45 troops, most of them Americans, compared with 35 deaths in 2011.

The attacks have sown deep mistrust between the Western allies and the Afghan security forces and threatened to undermine the U.S. plan to pull out its combat troops by the end of 2014 and leave behind an indigenous force strong enough to secure the country.

Meanwhile, the Taliban insurgency has also regained strength, stoking fears that the country will collapse into civil war as soon as U.S. and NATO troops withdraw.

NATO officials, in their own reviews of the insider incidents, have found that numerous military guidelines were not followed on both sides because of concerns that they might slow the growth of the Afghan army and police, whose numbers now total about 350,000.

The recent jump in the number of attacks prompted the U.S. military to announce Sunday that its Special Forces have suspended training of 1,000 new Afghan local police recruits so that current members can be vetted.

Officials estimate that the militant infiltrators into the army’s ranks are responsible for only a quarter of the fatal incidents. They say the rest appear to be motivated by a desire to avenge civilian casualties or to retaliate for perceived personal insults by coalition troops or more serious missteps, such as the burning of copies of the Koran and the desecration of enemy corpses.

The Afghan National Security Council acknowledged in August the role of cursory troop vetting and U.S. forces’ “inhumane acts” in insider attacks. But its months-long investigation pinned most blame on Pakistani and Iranian intelligence organizations, accusing them of recruiting young Afghans to join the army and police and brainwashing them to target coalition troops.

Karimi, addressing participants in an army literacy program Wednesday, said unspecified regional intelligence agencies were indeed working to undermine the nation: “Our enemies don’t want Afghanistan to be a self-sufficient country, our enemies don’t want Afghanistan to be an educated country, our enemies don’t want Afghanistan to be a united country,” he said.

But he also took his commanders to task for not educating the rank and file on the goals of the battle against Islamist extremism, including education for women and constitutional rights. Officers should also do more to help foreign troops understand Islamic traditions and values, he said, to reduce the possibility of violent responses to cultural slights.

“It is our duty to teach this to them. . . . Our indifference about these issues causes the incident,” he said, referring to an insider attack.

Some Afghan lawmakers expressed surprise at the Defense Ministry’s announcement about the expulsion and detention of troops.

“They should have shared this idea with us,” said Lalai Hamidzai, a member of the parliament’s internal security commission. “They should have asked our opinion.”

If the army had asked, it would have heard a familiar refrain: “We have told them many times in the past that intelligence networks of Iran and Pakistan have infiltrated into the ranks of the security forces,” Hamidzai said. “And that does not only involve the rank and file, but the leadership.”

Sayed Salahuddin and Javed Hamdard contributed to this report.