At least one person was Tuesday killed and five including Kenya Defence Forces soldiers injured in an attack by al-Shabaab militants along the Lamu - Ijara- Garissa road.
Witnesses and police said the gunmen targeted a convoy of vehicles.
The victims were construction workers on Lapsset road.
The injured were later evacuated and flown to the hospital, police said.
Police said the attack took place at about 8am marking the second such incident in a week.
According to police, the incident happened about seven kilometres from Bodhai Police Station/GSU camp in Garissa County as the group headed to their work stations from a Chinese camp where they reside.
A fuel tanker was hit by a rocket-propelled grenade (RPG) from the front, killing one occupant on the spot.
According to the police, the second car, a Foton Tipper, was hit from the rear and the other was a pickup which was attacked and burnt down.
It was then the responding security team was injured.
Witnesses said at least four of them were injured.
Northeastern regional police commander George Seda said the attackers escaped into a bush after the attack.
“We have sent more personnel to help in pursuing the attackers,” he said.
The incident comes a week after a similar roadside explosive killed four Kenya National Highways Authority (Kenha) engineers after the vehicle they were in hit an Improvised Explosive Device (IED) on the Lapsset road in neighbouring Bura East.
The team was travelling from Garissa to Hailey Chinese Camp and then to Bura East.
The situation forced the drivers of the other vehicles to return to Hailey Camp.
The same day, a rocket-propelled grenade missed a police General Service Unit vehicle.
It is the latest incident to happen in the same area amid concerns the terrorists In December last year, two police officers and a civilian were killed in a similar attack in the same area.
The terrorists are targeting projects including the Lapsset port and road.
A Chinese company is constructing the Bura-Garissa road connecting Tana River and Kilifi counties.
The road will lead to Garissa, Isiolo and later to Ethiopia and South Sudan.
The construction comprises of 257 km Lamu-Ijara-Garissa section, which is part of the Lapsset project.
Also, the 113-kilometre Hindi-Bodhei-Basuba-Kiunga section and the 83-km Ijara-Sangailu-Hulugho section.
Local police officials said they had deployed more personnel to pursue the gang operating in the expansive Boni Forest.
The LAPSSET Corridor Programme is Eastern Africa's largest and most ambitious infrastructure project bringing together Kenya, Ethiopia and South Sudan.
There are fears they are planning an attack on security agencies and civilians.
This has prompted operations spanning Mandera, Wajir, Lamu and parts of Kilifi counties.
The area is near the Kenya-Somalia border which has been under attack by terrorists in the past.