A suicide bomber targeting a bus of government employees near Kabul's biggest prison on Wednesday killed at least seven people, officials said, in the latest attack in the Afghan capital.

Another five were wounded in the blast near the facility, which police spokesman Basir Mujahid said had hit a vehicle that staff of Pul-e-Charkhi prison were travelling in.

The attacker was on foot, interior ministry spokesman Najib Danish said.

There was no immediate claim of responsibility for the explosion, but Daesh has claimed most suicide attacks in Kabul in recent months.

The attack comes days after a suicide bomber blew himself up near the entrance of Afghanistan´s Independent Election Commission in Kabul, killing at least one person and wounding six.