The United Nations today restricted movements of its staff in Kabul after a suicide bombing killed at least ten people.
Yesterday's bombing at a military training centre set up by US-led forces to train a new national army was the worst suicide attack in the capital since the Taliban's 2001 overthrow.
The Taliban claimed responsibility and said it had 45 more suicide attackers awaiting orders to strike.
UN spokesman Adrian Edwards said UN staff in the city, already under night-time curfew, had been placed on restricted movement as a precaution.
The security office serving non-governmental organisations has advised against unnecessary movement and told staff to stay on high alert.
In yesterday's attack, a suicide bomber in the uniform of an army lieutenant rammed a motorcycle into a convoy of buses carrying Afghan soldiers in the eastern part of the city, opposite a base of Nato-led peacekeepers.
The bombing came ten days after landmark parliamentary elections, which passed off relatively peacefully despite militant threats, but there has been a surge in violence since then.