Afghanistan's Interior Ministry says a roadside bomb has killed three charity workers and wounded two others, AP reported.
The ministry says Sunday's blast struck a vehicle carrying the charity workers to their office in Tarin Kot, the capital of Uruzgan province in south-central Afghanistan.
The ministry gave no further details.
It was the latest in a series of attacks to strike civilians in the violence-prone Uruzgan province, a longtime Taliban stronghold.
On Saturday one blast hit a convoy carrying a provincial council member from Wardak province, killing a bodyguard and wounding five others. Another explosion killed one policeman and wounded two in Kandahar.
Three NATO service members have died since Friday.