According to the Garowe Online news website, the incident took place in the remote town of Geedweyne on Tuesday, with the national authorities having blamed the Al-Shabab militant group for the kidnapping.
The abductees are reportedly Somali nationals working for global Christian NGO World Vision and the Ireland-based charity Trocaire.
Local elders have purportedly already launched negotiations with the kidnappers in a bid to secure release of the aid workers.
Al-Shabab emerged in Somalia in 2006 and has claimed to have undertaken numerous terrorist attacks throughout the region. The group has sworn allegiance to the al-Qaeda terrorist organization (banned in Russia).