Aminu Bello Masari said a total of 344 students detained in a wood in neighboring Zamfara state were released by their captors and handed over to security forces.
The governor said: “We have picked up most of the boys. They are not all ”.
He added that the boys will be medically examined and reunited with their relatives on Friday.
Earlier on Thursday, a video allegedly released by the jihadist group purported to show some of the students who were arrested last week.
Circulating on social media, the footage – with its logo – showed a group of young boys in the woods, begging security forces to leave the site.
Boko Haram claimed responsibility for the student kidnappings on December 11 in the pays northwest region – marking an expansion in the geography of the organization.
The attack on the government’s science high school – a boarding school for boys – saw gunmen armed with AK-47s breaking into the premises.
Hundreds of young boys were arrested and taken out of the building.
A joint rescue mission was launched with the Nigerian police, air force and army the next day on Saturday.
Since the kidnapping, protesters have marched in the area under a banner bearing the words #BringBackOurBoys – a popular hashtag Twitter – increasing pressure on officials to improve security in the region after the school attack.
A few days before the boys’ release, The United Nations Secretary General Antonio Guterres condemned the attack and called for “the immediate and unconditional release of the abducted children and their safe return to their families”.
Some of the youths were able to escape by jumping over the school fence and running to safety, after police exchanged gunfire with the attackers.
Last Friday’s raid on the school – which at the time had more than 800 students – evoked memories of the 2014 kidnapping of more than 270 girls by the terrorist group Boko Haram. in the northeast of Borno State.
Since then, only around 100 of these girls have been found or released.
Many have featured in propaganda videos and an unknown number are believed to have died.