GARDEZ, Afghanistan, (Reuters) - Unidentified gunmen have kidnapped 16 Afghans working for a United Nations-sponsored demining agency in eastern Afghanistan, UN officials and police said on Sunday. In a separate incident, two Afghan employees working for a Dutch aid agency were also abducted in a neighbouring province in the east on Saturday, the Afghan Health Ministry said. The Afghan deminers work for the Mine Detection and Dog Centre, part of the overall UN mine-clearing agency in Afghanistan known as UNMACA. They were seized while travelling between Khost and Paktia provinces late on Saturday, Paktias police chief said. We do not know who kidnapped them and why. We are investigating, Azizullah Wardak told reporters in the Paktia provincial capital Gardez. UNMACA official Gul Agha Ahmadzai said they were snatched as they drove along the Logar-Gardez road which links with Khost. In neighbouring Khost province, two Afghans working for HealthNet TPO (HNI), a Dutch aid agency, were abducted on Saturday, Health Ministry spokesman Ahmad Farid Raaid said. He had no further details. HNI is a Netherlands-based aid agency specializing in rehabilitating healthcare systems in war zones and disaster areas. It has projects in nine districts in Khost province, said Raaid. No group has yet claimed responsibility for either of Saturdays abductions, the latest in a surge of attacks and kidnappings by Taliban insurgents and criminal gangs. In Gardez last year, 13 deminers working for another agency were kidnapped by a criminal gang but were freed a month later after mediation by tribal chiefs. Kidnapping of Afghans and foreigners has become a lucrative business for both Taliban and criminal gangs in Afghanistan. Some captives have been killed, others have been released after ransoms were apparently paid.