Taliban fighters are expanding the fight to other northern provinces after Afghan government troops backed by NATO special forces evicted them from the centre of the strategic city of Kunduz.
Al Jazeera's Qais Azimy, reporting from Puli Khumri in neighbouring Baghlan province, said the Taliban had captured at least one district in each of the three provinces: Badakshan, Baghlan and Takhar.
The developments came the same day the Afghan government claimed it had successfully retaken Kunduz from Taliban fighters who had controlled the city since Monday.
President Ashraf Ghani, appearing at a televised press conference earlier on Thursday with his defence and interior ministers, said the city was retaken in a six-hour assault with no fatalities among the government security forces.
He praised the government troops, saying they "were able to foil one of the most significant operations to have taken place in Afghanistan in 14 years".
Ghani said the "good news" from Kunduz "should not make us complacent. The war is ongoing".
Sediq Sediqqi, spokesman for the interior ministry, said the operation to take back Kunduz was launched late on Wednesday, with ground forces moving from the airport, where they had massed since the city fell, over roads that had been mined by the Taliban.
Sediqqi said that control of Kunduz "was taken by 3:30am" on Thursday, but conceded that an operation "to clear the city is ongoing" and could take some days.
He said about 200 Taliban fighters have been killed in the fighting so far but did not provide a figure for government casualties.
Sediqqi told Al Jazeera the aim of the government counteroffensive was not only to secure Kunduz city but all the areas that the Taliban currently has under control and confirmed that a major security operation was under way.
Sarwar Hussaini, Kunduz police chief, said bodies of dead Taliban lay on the city's streets but that the clearance operation was complicated because some Taliban fighters had hidden inside people's homes.
Masoom Stanekzai, the defence minister, said sporadic clashes were still taking place as government forces continue to battle pockets of Taliban fighters.
"Small guerrilla forces remain in various neighbourhoods. We have to clear all the surrounding areas and open transport links so people can come and go," he said.
Al Jazeera's Azimy quoted a Taliban commander in Kunduz as saying, "We have enough military supplies from Kunduz city, which we can send to other parts of northern Afghanistan for use against government forces."
He said the Taliban had lost the centre of Kunduz but had taken up positions in surrounding residential areas.
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"They issued calls from mosque loudspeakers for people to come out in support of the Taliban and against government forces," he said.
One resident told Al Jazeera: "The Taliban came to my house to search for military supplies and when they could not find any, they asked me to join them as a soldier of jihad against infidel forces and assured me of a place in paradise after death.
"When I told them I had a family to take care of, they responded with three slaps and a warning that they would kill me if they saw me the next time around."
Our correspondent said Afghan troops joined by US special forces were using artillery and heavy machine guns, which resulted in several civilian casualties.
He cited doctors at Kunduz's main hospital as saying the facility had received more than 60 bodies so far and treated more than 420 people for injuries.
The majority of the casualties were civilians, including women and children, the doctors said.
They said the hospital was running low on medical supplies and suffering from a shortage of medicine and staff as many employees had run away.
"There is a shortage of food and no electricity. The only thing we can eat is a bullet from the sky," Al Jazeera's Azimy quoted one Kunduz city resident telling him over phone.
Doctors without Borders, the international charity which runs a trauma centre in Kunduz, said that since the city fell, it had admitted 296 wounded patients, 64 of them children and 74 in critical condition.
Kate Stegeman, the organisation's communication director in Afghanistan, said 40 people had died.
Noor-ul-Haq Ulumi, the interior minister, defended the performance of the Afghan government in the initial fall of Kunduz.
Hundreds of Taliban fighters apparently entered the city over the recent Eid holiday and lay in wait until their operation to take the city was launched early on Monday morning.
Earlier on Thursday afternoon, before Ghani's news conference, the Taliban denied they had lost Kunduz and Zabiullah Mujahid, the group's spokesman, claimed that it was still in their hands, saying "the Taliban flag is still flying" over Kunduz.
Source: Al Jazeera and agencies