The incident reportedly took place along Ikuru community in Adoni Local Government Area of Bayelsa State.
Also, another soldier was said to be missing just as the boat driver and three civilian employees of the Z-Cube Construction Company were also wounded in the attack.
It was learnt that the attack, which occurred on Tuesday afternoon, was carried out between the coastal border areas of Bayelsa and Rivers states.
A source, who preferred to be anonymous, said the soldiers were on an escort duty to provide security for the three-man team of Z-Cube Construction Company officials.