Four military officers were seriously injured when their vehicle hit an improvised explosive device in Gerrile, Wajir county.
The four, whose identities were not immediately established, were on their way back to the camp in a water bowser truck.
County commissioner John Chelimo said security officers were combing the area to find those behind the 7am incident.
"We are following a crucial lead," he said. "We will not allow these criminals to have a field day in a county that has enjoyed peace for all these months."
Attacks linked to terror group al Shabaab have been rampant in Garissa and Mandera counties.
The incident comes about three days after four people were killed and 11 injured when a PSV ran over an IED in Mandera. An area chief was among those who died in the attack.
More than 20 people, most of them security officers, have died in IED related attacks in Northeastern in a span of one and half months.
This has caused panic among residents who fear traveling on most of the county's roads.
But Northeastern regional coordinator Mohamud Saleh said the government was in control and doing everything possible to restore security and end the attacks.
Thank you for participating in discussions on The Star, Kenya. Note that:
- Unwarranted personal abuse and defamatory statements will be deleted.
- Strong personal criticism is acceptable if justified by facts and arguments.
- Deviation from points of discussion may lead to deletion of comments.