The threats were issued shortly after an Italian nun and her bodyguard were gunned down in the capital, Mogadishu on September 17.
The president of Somalia's weak interim administration, Abdullahi Yusuf Ahmed, narrowly escaped a suicide car bombing a day later.
Although no-one has claimed responsibility for the attacks, suspicion has fallen on the Islamic militias currently controlling wide swathes of the south and centre of the country, which deny involvement.
"Given the insecure environment and the subsequent direct written threats against UN staff, a decision was taken to temporarily relocate all UN international staff members from southern and central Somalia until further notice," the organisation said in a statement.
The UN said it had also pulled its global staff out of the autonomous state of Puntland, while all UN missions in Mogadishu had been suspended until further notice.
Stability risk
No details were given of the nature of the threats, nor the numbers of staff or when they were withdrawn.
"The rapid expansion of the influence of the Islamic courts... has posed a serious challenge to the status quo"
UN statement on Somalia |