Nato forces said they foiled a terrorist attack on a conference due to be held in Kabul to be attended by leaders from more than 60 countries.
Security was already tight across the capital for Tuesday’s conference, which is attracting the heads of Nato, the United Nations and top diplomats, including US Secretary of State Hillary Clinton.
Nato said a commando force captured a Taliban bomb-making expert on Friday night in Kabul.
Neither Afghan nor Nato officials would identify the suspect, give details of the plot, or say how advanced the planning was.
The Afghan Defence Ministry said several “enemies of the people” were killed and 26 were arrested.