Afghan officials say they have regained control of key areas of the northern city of Kunduz from the Taliban.
Report says,the operation launched overnight saw forces recapture government landmarks and inflict heavy casualties on the militants, officials said.
There has been no word from the Taliban, but fighting is reported to be ongoing
The city's capture was a huge blow to President Ashraf Ghani, coming on the first anniversary of his taking power.
Kunduz police chief spokesman Sayed Sarwar Hussaini told BBC Afghan on Thursday that the military had retaken the governor's office, the police chief's office and the intelligence agency building, adding: "Taliban bodies are lying around."
Pictures on social media purported to show government forces inside the city, which Afghan interior ministry spokesman Sediq Sediqqi tweeted was being cleared of insurgents.
If confirmed this represents a crucial victory for the Afghan army, its biggest test since the withdrawal of coalition forces back in December last year.