ABUJA, Feb. 10 (Xinhua) -- The three Asian doctors that were killed by unknown attackers in the northeast Nigeria's town of Potiskum are from Democratic People's Republic of Korea (DPRK), Nigerian police in northeast state of Yobe confirmed on Sunday.
State commissioner for police Sanusi Rufai told Xinhua that the health workers were killed in the early hours of Sunday. According to him, the health workers were posted to the Potiskum General Hospital.
"I can confirm to you that those killed are from North Korea and not Chinese or South Koreans" he said, adding that investigations had commenced to unveil those behind the murder of the expatriates.
A local resident of Potiskum town in Yobe state told Xinhua that the attackers also ransacked the house. Another security source in Potiskum told Xinhua that the gunmen stormed the premises through the back door.
Spokesperson for the military Joint Task Force (JTF) Lieutenant Eli Lazarus said he was aware of the attack, but had no further details.
No one claimed responsibility for the killing.
Potiskum has recently come under serious attacks by gunmen and bombers that staged an uprising in the northeastern city of Maiduguri in 2009, attacking state institutions including prisons, police stations and schools.
The attack came barely 48 hours after nine health workers were killed in attacks on two health centers where medics were conducting anti-polio vaccination in Nigeria's northern city of Kano.
The raid on Friday morning was the second this month, after unidentified attackers targeted a police division in Kano State, killing a police sergeant and another person.
Last month, the state government banned motorcycles, following an attack on the convoy of the prominent northern leader, the Emir of Kano Ado Bayero. At least four people were killed in the assault.
Kano State has witnessed waves of violence often claimed by the militant sect of Boko Haram. Thousands of people have been killed in northern and central parts of Nigeria since the sect launched insurgency in 2009.