Civilians, including a child, and security force members were among the casualties, according to Najib Danish, interior ministry spokesman.

He added that the suicide bomber was identified by police but he detonated his explosive vest before he could be safely apprehended.

Dostum's return

Dostum, who is linked to a number of of human rights abuses in Afghanistan, was mobbed like a celebrity as he left the chartered plane from Turkey where he has lived since May 2017.

Dostum's triumphant return was in stark contrast to the outrage he faced after reports in 2016 that his guards had seized political rival Ahmad Eshchi and subjected him to beatings, torture and violent sexual abuse.

He denied Eshchi's accusations but, amid international demands that he face justice to show that powerful political leaders were not above the law, he left the country in May last year, saying he needed to seek medical treatment in Turkey.

On Saturday, Ghani's spokesman said accusations against Dostum would be dealt with by independent legal authorities.

Once referred to as a "quintessential warlord" by the US State Department, Dostum has long been accused of serious human rights abuses.

Shortly after the US-led campaign in 2001, he was accused of killing Taliban prisoners by leaving them locked in airless cargo containers. He has denied the accusations. 

Afghan elections

Even in exile, Dostum remained a powerful figure with wide support among his fellow ethnic Uzbeks in northern Afghanistan.

President Ashraf Ghani now faces the challenge of reintegrating Dostum, an ally in the disputed 2014 election who helped deliver the ethnic Uzbek vote but a volatile and unpredictable partner ever since.

"I think the rehabilitation of General Dostum is a traditional part of the Afghan election season," Jarrett Blanc, Senior fellow at Carnegie Endowment for International Peace in Washington DC, told Al Jazeera.

"It happened prior to the 2009 election and of cause it famously happened when President Ghani selected him to be first vice-president in 2013 and it's happening again this year.

"By being the one bold enough to ask General Dostum to be his first vice-president, he was able to signal to all the power brokers in Afghanistan that he was somebody to be reckoned with and to launch himself to the second round and then into the presidency," Blanc said.

Dostum's return followed more than two weeks of demonstrations by supporters demanding the release of one of his militia commanders who was arrested following a dispute with officers in the regular security forces.

In remarks to his supporters, he made a brief reference to the commander, Nizamuddin Qaisari, who remains in custody pending an investigation.

But Dostum also called on protesters who had blocked roads and government offices in northern Afghanistan to end their demonstrations.