Gen Zahir resigned last week after presiding over a dramatic rise in militant attacks in recent months.
His spokesman sparked confusion days later by claiming his resignation had been rejected.
Interior ministry spokesman Sidiq Sidiqi said: "Abdul Rahman Rahimi, the former police chief of Balkh, is appointed as Kabul police chief and General Zahir is appointed as the head of the counter crime department.
"So far no-one is appointed as Balkh police chief and soon another general will be appointed there."
Gen Zahir gave no reason for his resignation, but he had faced increasing pressure, with insurgents carrying out nine deadly attacks in Kabul in the past two weeks.
The latest in a string of attacks targeted a compound used by a US-based charity on Saturday, killing three South Africans.
Last week, two American soldiers and two British embassy workers were killed in separate attacks, with dozens of Afghans also killed and injured.
Gen Zahir was himself the target of an attack in early November, when a suicide bomber infiltrated his offices and killed his deputy.
An Afghan policeman keeps watch outside the gate of a foreign compound following an attack by Taliban militants in Kabul on 30 November 2014. A building used by a US education group was attacked on Saturday
Afghan troops are preparing to take over national security before the withdrawal of foreign combat troops at the end of the month.
The Taliban stepped up attacks against foreign nationals, civilians and Afghan soldiers in recent months, raising concerns over the Afghan army's ability to protect the country from insurgents.
President Ashraf Ghani, who took power in September, has vowed to bring peace after decades of conflict.
On Sunday, he ratified security deals allowing some 12,000 Nato soldiers to remain for training and advisory purposes, after the withdrawal of foreign combat troops on 31 December.
The new law was intended to ease racial disparities in marijuana arrests.
When they passed the law in the spring, Washington DC city councillors noted that surveys show white and black people smoke marijuana at roughly the same rate, but in Washington DC black people were far more likely to be arrested and jailed for marijuana possession hair loss treatment.
Washington DC is not a state, and under the terms of the city's charter its laws are subject to review by Congress. At midnight on Thursday, the mandatory 60-day review period expired without Congress taking action, allowing the decriminalisation ordinance to take effect.
Formerly, possession of less than an ounce of marijuana was punishable by up to six months in jail and a fine of $1,000.china virtual office
Washington DC joins nine states in which possession of marijuana is treated as a civil, non-criminal offence, according to the Norml, a marijuana reform group.
In five other states marijuana possession is a misdemeanour punishable only by a fine. Alaska imposes no penalty at all for small amounts of marijuana, and the drug is legal in Washington state and Colorado Sim.