An estimated 100 demonstrators opposed to Shell's controversial onshore gas pipeline in Co Mayo this morning blocked workers from returning to the site.
Campaigners from the Shell To Sea group have been obstructing the entrance to the Corrib terminal at Bellenaboy since early this morning.
Construction workers were expected to return to the plant this morning after a year's absence. Gardaí are at the scene.
In a statement, Shell E&P Ireland, which is developing the Corrib Gas project, said it was disappointed that around 60 staff and contractors could not return to work because of the protests.
The company said it has full planning permission for the project and consent from all relevant authorities including Mayo County Council
It also insisted it has agreed to all the recommendations of an independent safety review of the project and accepted all of the recent proposals by independent mediator, Peter Cassells.
Terry Nolan, Shell E&P Ireland deputy managing director
Terry Nolan, Shell E&P Ireland deputy managing director, said the protesters did not represent the views of the wider community in the area.
"A small number of people who are unwilling to enter into reasonable dialogue should not be allowed to prevent work on the Bellanaboy gas terminal from recommencing," he said.
"We will consult with the relevant authorities following today's events but it is our firm intention to returnto work."
Shell said last week it has invited opponents of the project to new talks. Managing director Andy Pyle said the company had written to Dr Mark Garavan, of the Shell to Sea campaign, seeking talks over a new route for the onshore pipeline
Mr Pyle said that the company had "no intention of getting involved in any civil actions" against protesters and he hoped that any protests "would be peaceful".
Sinn Féin's natural resources spokesman, Martin Ferris TD, claimed "solidarity pickets" were to take place at Shell and Statoil filling stations throughout the State this evening.