State oil firm NOC had no immediate comment. Closing down an oilfield takes time. Engineers at the field had earlier given conflicting reports about whether oil was flowing or was being halted.
The tribesmen calling themselves the Fezzan Anger Movement were protesting to demand more development help for their community. Fezzan is the historic name of the southern region of Libya where El Sharara oilfield is located.
"We as the force securing the field inform you that the Fezzan Anger Movement entered the field and stopped the production in line with the demands of the movement," the local oil force guarding the facility said in a statement.
The group of tribesmen also said they had shut the field.
"El Sharara is closed. We had given authorities a deadline but we got no response," said the group's spokesman Mohammad Maighal.
The state oil firm NOC usually tries to avert such action through talks. (Reporting by Ayman al-Warfalli and Ahmed Elumami Writing by Ulf Laessing Editing by Edmund Blair)
(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)