A series of near-simultaneous attacks blamed on the Taliban have killed dozens of Afghan soldiers in the country's northern Kunduz Province, security forces say.

"We have suffered casualties. The Taliban has also suffered casualties," Afghan Defense Ministry spokesman Mohammad Radmanish told the AFP news agency on July 12.

He added that an air-and-ground operation against Taliban fighters was under way.

Officials said militants used night-vision goggles and fired artillery shells as they launched simultaneous raids on several Afghan military bases and posts in Kunduz's Dasht-e Arch district.

"Since we don't have the night-vision [goggles], the Taliban can get close to soldiers without them noticing," an Afghan commander told AFP.

Taliban extremists have bolstered their fighting capabilities by stealing U.S.-made Humvees, weapons, and other equipment, including night-vision goggles, during raids on Afghan military sites.

An official casualty total from the attacks was not immediately available. But AP and AFP quoted other security sources as saying that at least 30-40 security personnel had been killed and many others wounded.

Army spokesman Mohammad Hanif Rezaie said 15 soldiers were killed and 13 others wounded in a four-hour gunbattle at one security post in Dasht-e Arch.

In Takhar, a spokesman for the governor said an army base on the province border with Kunduz had been attacked and was now under Taliban control.

The spokesman, Sunatullah Timor, told AFP that 29 security personnel had been killed and another 17 wounded.

"No reinforcements have come to the area yet," he said.

In a Twitter statement, the Taliban claimed responsibility for the attacks and said its fighters had captured one army base and 11 posts, killing 65 soldiers and "many local police officers."

In a separate incident in the southeastern province of Ghazni, Afghan forces launched air strikes on a gathering of high-ranking Taliban members, killing 24 militants and wounding 17.

The Kabul government has struggled in the past year against resurgent Taliban fighters, as well as Islamic State (IS) and Al-Qaeda militants, nearly two decades after a U.S.-led coalition drove the Taliban from power in Afghanistan in 2001.

The Afghan Defense Ministry on July 8 said its forces had doubled their offensive operations against insurgents since the end of the government's unilateral cease-fire directed toward the Taliban.

President Ashraf Ghani declared an end to the 18-day truce, but he also called on the Taliban to resume peace negotiations. IS and Al-Qaeda were not included in the cease-fire.

So far, the Taliban have not responded to Ghani's offers for dialogue, instead demanding to sit down with the United States, which has dismissed this proposal.

The United States has some 14,000 troops in Afghanistan, providing the main component of the NATO mission to support and train local forces.

NATO leaders meeting in Brussels said they had agreed to "sustain our presence in Afghanistan until conditions indicate a change is appropriate" and that the alliance had extended financing for the effort through 2024.

"This will help them further develop their special forces and air force, as they continue to fight international terrorism. We also expressed strong support for President Ghani's bold peace proposal," NATO chief Jens Stoltenberg said on July 12.

With on reporting by AFP and AP