By Segun OwenYENEGOA, Nigeria, Feb 22 (Reuters) - Nigerian security forces repelled an attack by gunmen on an oil terminal operated by Italy's Agip in the Niger Delta late on Saturday, a military spokesman said.Gunmen in two speedboats attacked Nigerian troops guarding the Twon Brass oil terminal in Bayelsa state. Oil production at the facility was not affected."The attack was professionally foiled with no casualties on our side and the facility was intact," said Colonel Rabe Abubakar, spokesman for the joint military taskforce in the western Niger Delta.Nigeria's most prominent militant group, the Movement for the Emancipation of the Niger Delta (MEND), threatened this month to target Italian companies because of what it said was Rome's offer of two attack boats to the Nigerian military.Italy said it has offered cooperation and assistance to the Nigerian government in fighting drug trafficking and crime but there had been no specific offer to supply two military vessels.MEND is still holding two British oil workers kidnapped more than five months ago in the creeks of the Niger Delta, the heart of Nigeria's oil and gas sector.The group has accused the British government of offering military support to help Nigeria fight militant groups.Attacks by MEND have shut down more than a fifth of Nigerian crude oil production in recent years. (Additional reporting by Austin Ekeinde in Port Harcourt; Writing by Randy Fabi; Editing by Robert Woodward)