KABUL: Afghan President Hamid Karzai on Tuesday condemned a Nato operation that he said killed four children in the country’s east, a claim the coalition said was possible.

The operation took place in the Baraki Barak district of Logar province on Saturday, a statement released by Karzai’s office said, adding: “It resulted in the killing of four innocent children” who were tending to livestock.

Civilian casualties have been a major source of friction between Karzai’s government and the US-led Nato forces in Afghanistan.

“Despite repeated pledges by Nato to avoid civilian casualties, innocent lives, including children, are still being lost,” Karzai said in the statement.

A spokeswoman for Nato’s International Security Assistance Force (Isaf) said it was aware of possible ISAF-related civilian casualties from the Oct. 20 operation.

Figures it released on Tuesday showed that there had been a 58 per cent decrease in the number of ISAF-caused civilian casualties in July-September of this year compared to the same period in 2011.

Separately, a high-level Taliban commander in northern Afghanistan, Mullah Abdul Rahman, was captured in a joint Afghan-Nato operation, police and the German Armed Forces said.

“Rahman was involved in heightening insecurity in Kunduz, Takhar and Badakhshan provinces,” said Kunduz province police spokesman Sayed Sarwar Husseini. “He encouraged insurgents to plant roadside bombs and stage high-profile attacks on Afghan officials.”

For years after the ouster of the Taliban in 2001, northern Afghanistan was largely free of insurgent violence but security there, including in the three provinces Husseini mentioned, has been deteriorating over the past couple of years.

Also, in relatively peaceful Herat province, five Afghan soldiers and five policemen were killed when the Taliban launched an attack on a checkpoint on Monday, local officials said.

Husseini said Rahman, whom Nato has described as a “Taliban financier” in the north, was captured in Kunduz’s Char Darah district last Friday.

The German Armed Forces Operation Command in Berlin said German soldiers were involved in the joint operation, in which a man by the name of Abdul Rahman was captured, said spokesman Manfred Baumgartner.

German media said Germany’s elite KSK force was involved in the operation to capture Rahman, whom they said had orchestrated attacks on German soldiers.

Germany is the third-largest troop contributor to Afghanistan’s Nato-led force, after Britain and the United States.

With violence intensifying 11 years into the war, there is concern over how the 350,000-strong Afghan security forces will manage once most foreign troops leave by the end of 2014.