At least two of the killed were lecturers at Al-Biruni University.
The incident occurred when the bus they were travelling in was hit by an explosive planted on the road in the city of Charikar, capital of Parwan province, interior ministry spokesman Tareq Arian told reporters.
"Four people were killed and 11 were wounded," Arian told reporters.
The ministry of higher education said at least two of the killed were lecturers at Al-Biruni University from the neighbouring province of Kapisa, adding that the wounded included the dean of the university and some students.
The Taliban deny killing civilians.
Abdullah Abdullah, who heads the country's peace process, condemned the incident, which he called a "terrorist attack".
No group has so far claimed the bombing, and the Taliban denied they were involved.
Violence has soared in recent weeks as government forces and the Taliban clash in near-daily battles across the rugged countryside, with the insurgents pressing on with their campaign to capture more territory as peace talks remain deadlocked.
The Taliban deny killing civilians, but roadside bombs planted to target security forces often end up doing just that.
The group has also been accused of killing prominent Afghans including journalists, judges, civil activists and politicians in a wave of targeted assassinations in Kabul and other cities.
Even as violence surges, the US military continues to withdraw its remaining 2,500 troops from the country.
Last month, President Joe Biden ordered the US military to complete the exit of all troops by September 11, which will wrap up US on-the-ground involvement in a war that began nearly 20 years ago following the September 11, 2001 attacks by Al-Qaeda.Agence France-Presse
A truck packed with explosives blew up near a court in the eastern Afghan city of Gardez on Thursday, killing at least five people, two days after gunmen attacked a maternity ward in the capital Kabul, killing women and newborn babies.
The blast — for which no group has yet claimed responsibility — in the Afghanistan's restive Nangarhar province, a hotbed of Daesh activity, officials said. There was no official confirmation of the toll.
The events started with the detonation of a sticky bomb — a growing menace in Kabul, where insurgents and criminals slap magnetic bombs on the underside of vehicles.
Talks with North Korea should not be for political show but contribute to establishing peace, South Korean President Yoon Suk-yeol said on Wednesday, just hours after the North test fired two cruise missiles into the sea.
For the Aug. 29 mission, called Artemis 1, the Orion capsule will launch atop the Space Launch System without any humans and orbit the moon before returning to Earth for an ocean splashdown 42 days later.
Noeleen Heyzer's visit to the crisis-wracked country, which began on Tuesday, "will focus on addressing the deteriorating situation and immediate concerns as well as other priority areas of her mandate," the UN has said.