KABUL: An Afghan district police chief has been fired after one of his men killed a Nato soldier, marking the start of a crackdown on the increasing number of insider attacks, officials said on Tuesday.

The move came after President Barack Obama and top US military officers expressed growing concern over the so-called green-on-blue attacks in which uniformed Afghans turn their weapons against their Nato allies.

A total of 10 soldiers, mostly Americans, have lost their lives at the hands of their Afghan colleagues in the past two weeks, and the attacks have caused almost one in four coalition deaths in the war so far this month.

The police chief was sacked over the latest incident when a member of the Afghan national police opened fire on his foreign colleagues in the police headquarters of Spin Boldak district on Sunday, killing one and wounding another.

“The Spin Boldak district police commander has been fired for negligence in his duty and lack of control over his personnel,” the chief of police for Kandahar province, General Abdul Razik, told AFP.

“If he had control on his police personnel the latest attack on Nato would not have taken place.” he said.

The provincial government's media office, in a message on Twitter about the police chief's sacking, said green-on-blue attacks “will not be tolerated”.

“We stand by our partners. The provincial administration of Kandahar is committed to working closely with its international counterparts and avoiding the attacks against them.”

The move will be welcomed by the United States and its Nato partners in the international coalition helping the government of President Hamid Karzai fight a Taliban insurgency.

Nato and US officers have suggested the Afghan government has failed to come to grips with the problem and America's top military officer flew to Kabul for talks on the issue Monday with Nato commanders and Afghan top brass.

General Martin Dempsey, the chairman of the US Joint Chiefs of Staff, said he came away “reassured” after discussions with his Afghan counterpart, General Shir Mohammad Karimi.

“I am reassured that the Afghan leaders, military and civilian, understand how important this moment is,” Dempsey said before leaving Kabul on Tuesday.

The total death toll from insider attacks this year has already reached 40, which makes up 13 per cent of all international coalition deaths for 2012.