POTISKUM, Nigeria, Feb. 10 (Xinhua) -- Three Asian doctors have been killed by unknown attacker in the northeast Nigeria's city of Potiskum, local police said on Sunday.
State police commissioner Sanusi Rufa'i told Xinhua on phone that unknown gunmen scaled through wall guarding a building where experts believed to be Chinese or Koreans nationals and murdered three people.
A local resident of Potiskum town in Yobe state told Xinhua that the attackers also ransack 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.
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.
More than 1,500 people have been reportedly killed ever since, either in the attacks or clashes with local security forces.