The United Nations should withdraw all its personnel from Afghanistan as the country has become too dangerous to work in, the UN staff union has said.
The UN's work includes registering voters for elections in October
The union said staff should leave the country until new security measures had been introduced.
The union said UN personnel was likely to become a target in the run-up to October's elections.
"As we approach election time, more than likely attacks will intensify," union vice-president Guy Candusso said.
The union's call came days after a series of bombs exploded at a voter registration centre in western Afghanistan.
Afghan voters are due to elect a president in October and a new parliament in April.
A UN spokesman said that they had recently carried out a security assessment of the country and were putting extra measures in place.
"The overall security in Afghanistan is in the process of being upgraded," Stephane Dujarric told the Associated Press.
In July global medical aid group Medecins Sans Frontieres (MSF) announced it was leaving the country after 24 years, citing security fears
Thursday marked the one-year anniversary of attacks on the UN's headquarters in Baghdad which left 22 dead, including envoy Sergio Vieira de Mello.
An independent inquiry ordered by Secretary General Kofi Annan found that the UN's security management system at the time was dysfunctional.
Mr Annan has said that the organisation is now wrestling with the difficult question of how to remain involved in areas where staff are increasingly under attack.
"How do we operate in places like Iraq and some parts of Afghanistan, where many people want and expect us to help... but some are determined to block our work at any price?" he said on the anniversary of the attack.