Gunmen kidnapped two South Korean missionaries in northern Kenya, near the border of Ethiopia, on Monday evening while eight Kenyans were shot dead in a separate incident in the region, local officials said.

The arid borderlands between Kenya and Ethiopia are awash with weapons and suffer frequent raids by armed groups, and last year the government launched a security operation to disarm local bandits and bring calm and order to the region.

"Two missionaries of Korean origin were abducted and (are being) held incommunicado to date," Marsabit County Governor Mohamud Ali said in a statement on Tuesday.

The Standard newspaper quoted Marsabit County Commissioner James Kamau as saying a South Korean male and his mother-in-law were taken from their home in the village of Odda on Monday around 9 pm.

The man's mobile phone signal was last traced to the border with Ethiopia, Deputy County Commissioner David Saruni told Reuters late on Tuesday. "Efforts to locate him have been futile since the phone has been switched off," Saruni said.

The South Korean embassy in Nairobi did not immediately respond to an emailed request for comment. National police spokesperson Resila Onyango said she was aware of the abduction but could not provide further details.

In another attack on Monday night, gunmen in "jungle attire" shot dead eight people and burned their bodies beside the lorry they were travelling in around 100 km west of the city of Moyale, according to a police report seen by Reuters.