Afghan officials say dozens of Taliban fighters staged overnight raids and stormed several checkpoints in the northern part of the country, killing at least 14 security personnel.
The violence early on June 23 comes after authorities this week accused the Taliban of increasing attacks on Afghan forces at a time when both sides say they are preparing to start delayed peace negotiations.
Officials said simultaneous raids on one army and two police checkpoints in Kunduz Province led to fierce gunbattles that lasted for hours.
Eight members of the Afghan security forces were killed and seven more were wounded in the fighting, district chief Nasruddin Saadi said.
The Kunduz provincial governor's spokesman, Esmatullah Muradi, confirmed the attacks but said nine security personnel were killed in the nighttime battle.
The Taliban has so far not commented.
Militants also raided an army post in Balkh Province and another in Ghazni Province during the night, the Defense Ministry said, adding that several insurgents had been killed in ensuing clashes.
At least six Afghan police officers were killed and one wounded in another attack in the Chahar Bolak area of Ghazni, local officials told TOLOnews.
Violence dropped across much of Afghanistan after the Taliban announced a three-day cease-fire on May 24 to mark the Eid al-Fitr holiday, but officials now accuse the insurgents of stepping up attacks.
The National Security Council said on June 22 that the Taliban had killed at least 291 Afghan security personnel over the past week, saying it was the "deadliest" week in the 19-year conflict.
President Ashraf Ghani told a government meeting on June 22 that the violence unleashed by the Taliban was "running against the spirit of commitment for peace."
Ghani has vowed to go on with a Taliban prisoner release as agreed in a deal between the militants and Washington in February.
Afghan authorities have already freed about 3,000 Taliban inmates and plan to further release 2,000 as stipulated in the deal as a condition for talks.
The militants have released 500 prisoners they were holding.