Afghan President Ashraf Ghani has dismissed Masoud Andarabi as interior minister, after a spate of attacks against the country's security forces.
Mr Ghani on Friday appointed former Helmand governor Hayatullah Hayat as Acting Interior Minister, the National Security Council said.
The president also appointed Army Chief of Staff Gen Yasin Zia as Acting Defence Minister until Asadullah Khalid recovers from an illness which has hospitalised him for months, the council said.
It did not give further details on Mr Andarabi's dismissal but a senior security official said that the former minister had failed to arrest a militia commander whose forces shot down a helicopter in central Wardak province on Thursday, killing nine security force members.
The official said Mr Ghani had asked Mr Andarabi to arrest the militia commander weeks ago, and that the commander was responsible for a number of other attacks against Afghan security forces in recent months.
Mr Ghani told reporters on Thursday that the helicopter had been shot down and the perpetrators would be arrested and punished.
Mr Andarabi did not respond request for a comment.
Abdullah Abdullah, Mr Ghani's main political rival, opposed Mr Andarabi's dismissal, saying it was "against national interests and is unacceptable", the Afghan Tolo News agency reported.
Mr Abdullah said the move contravened the political agreement reached with Mr Ghani on the formation of a government following a disputed presidential election in September 2019.
The minister's dismissal comes as government forces prepare for a renewed spring offensive by Taliban insurgents, which international players fear will further endanger the nation's fragile peace process.
Typically there is a lull in fighting during the snowy winter months before renewed attacks around March.
Mr Abdullah, who heads the government council in charge of reconciliation efforts, held talks with the Taliban in Moscow on Friday, after an international conference on the peace process hosted by Russia.
The Afghan government and the Taliban said after the meeting that they had agreed to try to accelerate peace talks.
During the conference, held just six weeks before a deadline agreed last year to withdraw US troops from Afghanistan, the US, Russia, China and Pakistan called on the warring sides to reach an immediate ceasefire.