The militants also captured dozens of soldiers in two days of fighting following an attack on an army base in Faryab province. Separately, fighting entered the fifth day in the northeastern city of Ghazni.
Taliban militants overran large parts of an army base in northern Afghanistan, killing at least 17 soldiers, wounding 19 and capturing dozens more in fighting over the past two days, officials said on Tuesday.
The insurgents had captured tanks and ammunition in Chenayeeha army base, in Ghormach district of Faryab province, in an offensive that began on Sunday, according to Mohammad Tahir Rahmani, head of the provincial council.
"We have not been able to enter the base. Large parts of the base are still under the Taliban control," Rahmani said.
TRT World's Sultan Faizy brings the latest from the capital Kabul.
Another provincial official added that the Taliban had captured 40 soldiers, but 30 militants had also been killed in the fighting.
Taliban spokesman Zabihullah Mujahid claimed responsibility for the attack in Faryab.
He says 57 Afghan soldiers surrendered to the Taliban while 17 others were captured in battle. He says eight military Humvees were seized.
Fighting enters fifth day in Ghazni city
Afghan officials say security forces have pushed back the Taliban from Ghazni and are now trying to flush the insurgents from the city's outskirts.
The operations come on the fifth day after a massive Taliban attack on the provincial capital of Ghazni.
Hundreds of people have fled the fighting in Ghazni, which has killed about 100 members of the Afghan security forces and at least 20 civilians.
'Searching every inch'
Nasart Rahimi, a deputy spokesman at the interior ministry, says security forces were searching every inch of Ghazni for Taliban fighters on Tuesday.
Abdul Karim Arghandiwal, an army media officer in southeastern Afghanistan, says military helicopters are supporting the ground forces' operations in Ghazni.
Taliban spokesman Zabihullah Mujahid denies the insurgents have been routed from Ghazni and says sporadic gunbattles are still ongoing.
Blow to President Ghani
Ghazni is a strategic centre on the highway that links Kabul to the country's south.
People fleeing Ghazni have described bodies in the streets, while aid groups said hospitals are struggling to take in the wounded.
The Taliban's siege is a blow to President Ashraf Ghani weeks before a parliamentary election, and dashes hopes the two sides could begin peace talks.
On Monday, after days of silence, Ghani said on Twitter that reinforcements would be sent to the city and the defence minister said special forces had been dispatched.
Defence minister Lt Gen Tariq Shah Bahrami said Afghan forces were ready to defend their people.
"Our message to the people of Afghanistan and especially for Ghazni residents is that Afghan security forces are ready to defend their people and country at any time by accepting sacrifices in the battlefield."
US forces are on the ground helping to co-ordinate air strikes while the US military said it's launched at least two dozen air strikes since Friday.
US soldier killed
Meanwhile, the Pentagon has that a US special operations soldier had been killed in a bomb blast in Afghanistan's Helmand province on Sunday.
Staff Sergeant Reymund Rarogal Transfiguracion died after an improvised explosive device detonated near him while he was conducting combat patrol operations.
The 36-year-old from Hawaii was assigned to the 3rd Battalion, 1st Special Forces Group.
While Afghan security forces are conducting most of the fighting against the Taliban and other insurgent groups, US troops operate alongside them in a training capacity and are frequently on the front lines.