"We have received four resignations by two ministers and two senior security officials," said an official in President Ashraf Ghani's office on Saturday.

Another source confirmed the news, noting that Defense Minister Tariq Shah Bahrami and Interior Minister Wais Barmak had resigned.

He added that the head of the National Directorate of Security Masoom Stanekzai had also handed in his resignation.

Earlier in the day, a spokesman for the Afghan National Security Council confirmed that Mohammad Hanif Atmar had resigned. Following the announcement Ghani's office said that he had been replaced by the Afghan Ambassador to the US Hamdullah Mohib.

A copy of Atmar's resignation letter was published by Tolo News, in which he said he resigned due to "serious differences over policies and approaches at the top level of government."

"Because of my differences of these things in recent months I am stepping down because we haven’t reached a consensus," it added.

A senior government official claimed that Atmar resigned as he was considering running against Ghani in the 2019 presidential elections.

“He has resigned because he is preparing to run for presidential election next year,” said the official on condition of anonymity.

The resignations come at a time a diminished security situation in Afghanistan, which has been hit by several deadly attacks over the past few weeks.

Earlier in the day, at least three people have been killed in a bomb blast in the eastern Afghan province of Nangarhar.

Afghanistan has been gripped by insecurity since the United States and its allies invaded the country to topple Taliban as part of Washington’s so-called war on terror in 2001. Many parts of the country remain plagued by militancy despite the presence of foreign troops.