THE MEN were murdered in front of their wives in the compound the three couples shared in the town of Potiskum, 300 miles northeast of Abuja, the capital. The state police commissioner confirmed the killing but refused to speculate on whether they were linked to Boko Haram, the al-Qaeda-allied sect that is terrorising northern Nigeria in a bid to rule it under strict Islamic law. The group is believed to have ordered the targeted shooting on Friday of nine health workers in Kano. The doctors were said to have been on contract to the Yobe state health ministry and had lived in Potiskum for close to a year, according to residents. There was no official confirmation whether the men were from North Korea or South Korea. Officials in Seoul said they understood very few South Koreans were in the area. The attack, in the early hours of yesterday morning, was the latest in a spate of killings of foreigners, especially Chinese nationals, in the country's restive northeast. In November, gunmen shot dead two Chinese construction workers in nearby Borno State, the stronghold of the Boko Haram extremists. Three other Chinese nationals have also been killed in separate attacks in the region.