An explosion on Friday outside an entrance to Kabul University in the Afghan capital killed at least seven people and injured 27 others, officials said.
Health ministry spokesman Wahid Mayar said there were students among the 27 injured taken to hospital after the blast, which a student at the university campus said took place while a number of students waited to appear for an exam.
Afghan security forces are facing almost daily attacks by Taliban militants, despite reported progress in efforts by the United States to broker an end to Afghanistan's nearly 18-year war.
There was no immediate claim of responsibility for Friday's blast just hours after Taliban militants set off two car bombs outside police headquarters in the southern city of Kandahar, killing at least 12 and wounding more than 80.
A student at the university campus said the explosion happened when a number of students were waiting near the campus gate to attend an exam. An eyewitness said that a vehicle caught fire after the explosion.
Kabul police spokesman Faramarz Firdaw said a police team defused a second bomb that was placed close to the explosion site near a university gate.