Al Shabaab militants killed two non-local teachers on Tuesday and burnt the staff room at Arabia Boys Secondary School in Mandera East subcounty.
The attackers armed with guns and grenades stormed the school at 1am.
They proceeded to the teachers quarters, killing the two on the spot as they tried to escape.
They then hurled a grenade at the houses and the classrooms , setting a fire that razed them.
Police reservists who guard the school are said to have engaged the militants in a gun battle before being overpowered.
The slain teachers were flown to Nairobi where their next of kin will be notified.
The murders come barely a day after the area Knut representative told the government to heighten security ahead of the national exams.
Northeastern regional commissioner Mohamed Birik said all the other teachers and students are safe and have been accounted for.
“It appears the militants are determined to advance the narrative of targeting non-locals with the aim of pitting Kenyans against each other. I can assure them that they will never succeed. Such acts only make us stronger,” said Birik.
Area MP Omar Sheikh urged for calm among both teachers and students.
The school is near the border with Somalia, not far from where 28 teachers were killed in 2015.
The militants hurled the grenade where the non-locals stay, an indication that they knew their target well. Lafey MP Abdi Mude urged the government to increase security to prevent future attacks.
“I have spoken time and again about the need to put extra security in school neighbouring the border.
Surely we don’t have to wait for such killings before we can act.
Hundreds of innocent lives have been lost. For how long will we continue losing livest o militants?” Mude asked.
Birik urged parents, students and education officials not to panic.
“I assure Kenyans from that part of the country that sufficient security has been put in place for the national examination,” Birik said.
He said routes have been marked and personnel increased for every exam container. All nine border subcounties are safe, he said.