Three South Korean doctors were killed by yet unknown persons in Potiskum, Nigeria's northern Yobe State, on Sunday, two days after nine polio vaccinators were killed in Kano, also in northern Nigeria, the local Sunday Trust newspaper reported.
The paper quoted the Yobe State Commissioner of Police, Mr. Sanusi Rufai, as confirming the killings, saying: 'It is true. The three doctors were slaughtered while sleeping in their house.'
The police boss said the corpses of the doctors have been deposited at the Federal Medical Centre in Azare.
He was silent on the nationality of the doctors, but the Sunday Trust quoted sources at the Potiskum General Hospital, where they have worked for the past one year, as saying they were all male and South Koreans.
The paper said the killers jumped the fence into the doctors' house at T Junction area of the Potiskum local council of the state and slaughtered them around 1.30 am local time on Sunday.
The killings occurred despite a night-time curfew in the state, which has been the hotbed of activities by the violent Islamic sect Boko Haram.
It is not yet known whether the killings are part of a new trend to target health workers in the predominantly-Muslim northern Nigeria, following the killings of nine polio vaccinators in Kano on Friday.
Yobe has been a hotbed of attacks by Boko Haram, which launched its violent campaign in 2009 following the killing of its leader, Mohammed Yusuf, by the police.
Since then, it has killed over 3,000 people in gun and bomb attacks, according to the Nigerian Army.