Police commissioner Sanusi Rufai told the AFP news agency that armed men had entered the doctors’ flat in the town of Potiskum and slit their throats.
There were contradictory reports about the victims’ nationalities, with one saying they were South Korean and another that they were Chinese.
Mr Rufai said no-one had been arrested yet in connection with the attack.
“It is still premature to point any accusing fingers but we have commenced investigation to unravel the killings,” he said.
No group has yet said it was behind the attack on the doctors, which reportedly happened either late on Saturday or before dawn on Sunday.
Local officials told the Associated Press that the victims had all worked at the General Hospital in Potiskum and that they routinely travelled through the town without security guards.