Afghan President Ashraf Ghani announced a ceasefire with Taliban insurgents from Monday to mark the Muslim Eid al-Adha holiday, days after fighting in the central city of Ghazni and a northern province.
A provincial council member in Kunduz said "a total of 300 to 400 passengers" could have been on the buses when the militants stopped them.
Mujahid said top leaders had not declared a ceasefire, but they would release at least 500 prisoners, including members of the Afghan security forces on Monday, a day before Eid celebrations begin.
Esmatullah Muradi, a spokesman for the governor of Kunduz province, said the kidnapping happened when three buses were travelling through Kunduz from Takhar province, on their way to the capital, Kabul.
This month the Taliban fought an intense battle with Afghan forces to control the strategically important city of Ghazni.
"I once again announce a ceasefire from tomorrow until the prophet's birthday provided that the Taliban reciprocate", said Ghani, referring to the Prophet Mohammed's birthday which Afghanistan celebrates on November 21.
On Saturday, the leader of the Afghan Taliban, Maulvi Haibatullah Akhunzadah, said that there will be no peace in the country as long as the "foreign occupation" continues.
The Taliban have stepped up their assaults in recent months, seizing entire districts across Afghanistan and regularly carrying out large-scale bombings and attacks that have killed scores of people.
The Taliban accepted the three-day truce but rejected calls by Ghani to extend it.
"We made a decision to seize the buses after our intelligence inputs revealed that many men working with Afghan security forces were travelling to Kabul in these buses", Zabihullah Mujahid, a spokesman for the Taliban, said by telephone.
KABUL-Afghan President Ashraf Ghani on Sunday proposed a conditional three-month cease-fire in the government's USA -backed war against the Taliban, seeking to regain political momentum following a string of devastating battlefield losses to security forces at the hands of the insurgents. Since then, American forces, now in a training and advising role, have repeatedly come to the aid of Afghan forces.