YENAGOA, Nigeria, Nov 30 (Reuters) - Italian oil company Eni confirmed on Tuesday that Nigerian gunmen killed three contractors and wounded another two in the Niger Delta, where it said the security situation was precarious.

A local security spokesman told Reuters on Sunday that four people had been killed in the attack.

Eni said in a statement that the workers, who were working on a project to restore mangroves in the Delta swamps were attacked by an armed group "causing as far as we know three fatalities and two injuries."

"A very precarious and worsening general security situation is confirmed in the Swamp area, which put in danger and harms the company people and contractors, as well as the local communities," said Eni.

The Delta, which produces the bulk of Nigeria's oil but is chronically underdeveloped, has been plagued by pirates, politically motivated militants and a range of armed criminals. (Reporting by Tife Awolabi; Writing by MacDonald Dzirutwe; Editing by Andrea Ricci)