Gardaí said today they used a "minimum of force" to remove protesters from the construction site of Shell's onshore gas terminal in Co Mayo early this morning.
Two protesters were hurt at the site as a team of 170 gardaí carried out a major operation to allow security guards and workers enter the facility.
Local TD Dr Jerry Cowley said a woman (21) suffered severe shock and bruising to her neck when pushed back by gardaí who were clearing a path for Shell security guards to enter the Bellanaboy site early this morning.
But gardaí said the woman was hurt during a "crowd surge" by protesters.
Dr Cowley said the woman was injured when she was pushed back by gardaí who had linked arms despite pleas by her to stop.
"She was lifted up by her chin and pushed back. I treated her, and she had a lot of abraisions on her neck which was a sign she was traumatised and she could hardly breathe when I saw her."
Dr Cowley, who supports the protests, said he treated her before an ambulance arrived and she was later taken to Mayo General Hospital in Castlebar.
Inspector Ray McHugh of the Garda Press Office said there was a "crush-type scenario" after a "crowd surge" as officers cleared a path for Shell security guards to enter the site.
"As far as we are concerned we acted in a professional manner and a minimum of force was used." He said he was "delighted" that the protest was "very peaceful".
"We are not interested in getting involved in conflicts with local people," he added. "The purpose of the operation was to free up access to a place of work and twinned with that provide an area for a lawful protest."
He said the Garda would maintain a presence in the Bellanaboy area "as long as we have to. We are not putting a timeframe on it".
Gardaí are still at the scene this afternoon.
Philip McGrath, one of five men jailed over their objection to Shell's onshore facility last year, was also hurt this morning. He recieved a soft tissue injury to his thumb, according to Dr Cowley.
The Garda operation began at 3am, when gardaí closed off roads, towed away cars and put up crowd control barriers as the local protesters gathered at the entrance to the site. Some 60 protesters were forcibly removed by officers without resistance.
Protesters stood outside the site last week and prevented the contractors entering.
Shortly before 8am the workers were brought in in a convoy of 10 cars and a number of trucks, escorted by gardaí.
Dr Mark Garavan of the Shell-to-Sea Campaign told ireland.comthe Garda operation was "hugely over the top since the protest has always been peaceful.
"We don't have any issue with the gardaí . . . they have a job to do. But freedom of protest and freedom of assembly has been curtailed.
"The Irish Government are now actively engaged since early morning on the side of Shell against the local people who will not risk the safety of their families for a project that has little if any financial benefit for the Irish people. This is serious escalation of the dispute."