NIGERIA, Potiskum - Yobe State: Unknown Assailants Kill 3 North Korean Doctors, Beheading One Of The Physicians. :(

Here is how ALJAZEERA are reporting it: Three South Korean doctors (they are now confirmed to have been North Korean - see red highlight below) have been killed in a pre-dawn attack in Nigeria's northeastern town of Potiskum, police say. The motive of Sunday's attack was not immediately clear, but a security source told Al Jazeera that preliminary reports suggested it was a robbery that resulted in the medics' deaths. Yobe State police commissioner Sanusi Rufai, initially said the victims were Chinese. "Unknown attackers scaled over the fence of an apartment in Potiskum housing three Chinese doctors around 1am and slit their throats. No arrest has been made," he told the AFP news agency on Sunday. Residents said the dead were employees of the state ministry of health and had been living in the volatile city for one year. Nine health workers who were administering polio vaccinations were shot dead in the northern city of Kano on Friday. Kano, Nigeria's second largest city, has been regularly targeted by Boko Haram, an armed group which has condemned the use of Western medicine. The group is also active in Potiskum, where Sunday's killings happened, but there was no immediate claim of responsibility for the killings. "It is still premature to point any accusing fingers but we have commenced investigation to unravel the killings," Rufai said. CTV News version below sounds more accurate, with updated info: Assailants in North-Eastern Nigeria killed three North Korean doctors, beheading one of the physicians, in the latest attack on health workers in a nation under assault by a radical Islamic sect, officials said Sunday. The deaths Saturday night of the doctors in Potiskum, a town in Yobe state long under attack by the sect known as Boko Haram, comes after gunmen killed at least nine women administering polio vaccines in Kano, the major city of Nigeria's predominantly Muslim north. The two attacks raise new questions over whether the extremist sect, targeted by Nigeria's police and military, has picked a new soft target in its guerrilla campaign of shootings and bombings across the nation. The attackers apparently struck at the North Korean doctors inside their home, said Dr. Mohammed Mamman, chairman of the Hospital Managing Board of Yobe State. The North Korean doctors had no security guards at their residence and typically travelled around the city via three-wheel taxis without a police escort, officials said. By the time soldiers arrived at the house, they found the doctors' wives cowering in a flower bed outside their home. At the property, they found the corpses of the men, all bearing what appeared to be machete wounds. An AP journalist later saw the North Korean doctors' corpses before they were moved to nearby Bauchi state for safe keeping. Two of the men had their throats slit. Attackers beheaded the other doctor. The doctors lived in a quiet neighbourhood filled with other modest homes in the town. Initially, doctors at the hospital who worked with the physicians identified them as being from South Korea, while police identified the dead as being from China. Ultimately, Mamman of the health board told journalists those killed were from North Korea and had lived in the state since 2005 as part of a medical program between the state and the North Korean government. Yobe state police commissioner Sanusi Rufai confirmed the attack took place and said officers had begun an investigation. Rufai said officers had made some arrests after the killings, though police in Nigeria routinely round up those living around the site of a crime, whether or not there is any evidence suggesting their complicity. No one claimed responsibility for the attack, though suspicion fell on the Boko Haram sect. The killings of the doctors come after the attack Friday on polio vaccinators in Kano, northern Nigeria's most populous city. No group has yet claimed responsibility for that attack either, though it follows alleged Boko Haram attacks now focusing on softer targets, like lightly guarded mobile phone towers. Those mobile phone tower attacks have limited the ability of residents and security forces to call for help during attacks, as well as have cut the government's ability to use the signals to track suspected militants. Boko Haram, whose name means "Western education is sacrilege," has been attacking government buildings and security forces over the last year and a half. In 2012 alone, the group was blamed for killing at least 792 people, according to a count by AP. The sect, which typically speaks to journalists in telephone conference calls at times of its choosing, could not be reached for comment Sunday. In recent months, however, Boko Haram has not claimed any attacks, raising questions about whether the shadowy sect that already had a loose command-and-control structure had splintered into smaller, independently operating terror groups. Since late 2011, Potiskum, about 500 kilometres (300 miles) northeast of Nigeria's central capital, Abuja, has been targeted by Boko Haram fighters in attacks. The attacks killed dozens at a time and brought the deployment of a heavy contingent of police officers and soldiers to the town. For the last few weeks, however, the town has been quiet. Soldiers still mount a series of checkpoints throughout the town, where in the past the military has put neighbourhoods in lockdown and launched door-to-door searches for militants. In a statement Friday, President Goodluck Jonathan condemned the killings of the polio workers and promised that efforts to cut child mortality wouldn't be stopped by "mindless acts of terrorism." "While the government will continue to do everything possible to track down and apprehend agents of terrorism in the country, the president has directed that enhanced security measures be put in place immediately for health workers in high-risk areas," the statement read.