MANDERA, Kenya, Aug. 13 (Xinhua) -- At least three people were killed and two others seriously injured on Monday after their civilian vehicle ran over an improvised explosive device in Mandera, northeast Kenya, along the Somali border, police confirmed.

Mandera East Divisional Police Commander Daniel Chacha, who confirmed the incident, said the victims were involved in the construction of a border wall.

They were clearing a road along the security wall when the explosion happened on Monday morning.

Mandera South Deputy County Commissioner Paul Kemei also confirmed the incident, saying the team was headed to their work station when the device exploded.

"The victims were hit by what we suspect to be an improvised explosive device," he said.

Kemei said the team is usually given security escort to the site and wondered why police officers did not accompany them on Monday.

The incident is likely to cause panic among the workers who have been helping Kenyan army officers in the construction works.

The wall is manned by Kenya Defense Forces (KDF) soldiers who are already on the ground. A surveillance road is also being built, running parallel with the barrier, for easier monitoring of the border.

Kenya began constructing the security wall that runs to the coastal town of Lamu in April 2015 to help prevent Somali militants from crossing into Kenya to carry out terror attacks.