13 policemen have been killed after suspected militants ambushed their boat in a creek at Zuzama in southern Ijaw local government area of Bayelsa state.
Three others including a police sergeant escaped death by swimming away to safety.
According to the commissioner of police in the state Kingsley Omire, the boat carrying the police officials was headed to a funeral when it developed engine fault.
It is still unclear if the Movement for the Emancipation of the Niger Delta (MEND) is responsible for the attack.
In an e-mail last week, the group had threatened to resume killings in the region following the jailing of its leader Henry Okah by a South African court.
