A man and a woman are being questioned at Belmullet Garda station charged with public order offences at the Corrib gas terminal in Mayo this morning.
Two people have been hospitalised with head injuries, after gardaí baton-charged a crowd of about 200 protestors who were blocking a convoy of construction workers at the Bellanaboy site.
The Shell to Sea protest group’s Day of Action sparked off violent scenes.
But gardaí succeeded in moving the convoy of workers through to the site.
Demonstrators have been staging protests there every morning since October 2.
The Taoiseach has said that he will not intervene in the conflict.
Bertie Ahern said he believes that all reasonable concerns have been dealt with adequately by this stage with the Cassels Report and the technical advisory group.
Meanwhile, demonstrations will take place at Shell Headquarters around the world today to mark the 11th anniversary of the execution of Ken Saro-Wiwa and eight other anti-Shell activists in Nigeria.
A wreath will be laid at Shell's Headquarters in Dublin this lunchtime.