Three miners were on Thursday night killed by suspected Al Shabaab militants at a quarry in Mandera South.
Two others were also injured in the attack.
The incident occurred at Shimbir Fatuma, which is about 65 kilometres from the Kenya-Somalia border.
There are claims that the quarry workers had earlier defied government orders to vacate the area following increased cases of Al Shabaab attacks.
Earlier this month, the Kenya Defence Forces rescued 13 Kenyans from Al Shabaab militia.
They had been abducted during a fishing expedition in Malindi.