The killings in this part of Nigeria seems to be taking a different trend towards the Health services, after the gruesome murder of nine Nurses administering Polio vaccines, come the killing of three South Korean doctors in the north-eastern Nigerian state of Yobe.
Residents said they were killed during the night in the town of Potiskum. Two of them had their throats slit while the third was beheaded, they added.
Officials said the victims had been working at a government-run hospital.
No-one has said they were behind the attack, but it happened in an area where the Islamist militant group, Boko Haram, has been active in recent years.
Yobo state police commissioner Sanusi Rufai said it was nevertheless too early to know who was behind the attack, which happened either late on Saturday or before dawn on Sunday. Police have begun an investigation.
The victims were reportedly found inside their flat on Sunday morning, after people became worried that they were not answering the door.
An official at the General Hospital in Potiskum told the Associated Press that the victims were South Korean and had worked there.