Unidentified gunmen have shot dead an employee of the UN refugee agency in Somalia's capital Mogadishu, in an attack that also left another person dead.
"It is with great sadness that UNHCR has learned of the killing of one of our colleagues, Amina Noor Mohamed, this afternoon in Mogadishu, Somalia," a UNHCR statement said.
The Geneva-based agency said Mohamed was killed by "unknown gunmen while travelling in a private vehicle driven by a staff member from a UNHCR partner organisation who also lost his life in the attack."
While there was no indication of who was responsible, aid workers including UN staffers have previously been targeted by Shebab Islamist militants battling a weak, internationally-backed government.
UNHCR chief Antonio Guterres said the attack "serves as another stark reminder of the dangers many humanitarian workers face in their daily work".
Mohamed, who had worked in Mogadishu since 2011, left behind two young children, aged two and three months, UNHCR said.
Guterres added that UNHCR staff would observe a moment of silence for Mohamed at the agency's headquarters in Geneva on Tuesday.
Four employees of the UN's children's agency (UNICEF) were killed in April when Shebab members set off a huge bomb that ripped through a staff bus in the northeastern town of Garowe.
In claiming that attack, the Al-Qaeda-affiliated Shebab insurgents, branded the UN a "colonisation force in Somalia".