GREENPEACE activists attached themselves to survey equipment about 70 miles North-west of Lewis yesterday as the group stepped up its campaign against Atlantic oil exploration.

It claimed four activists climbed onto floating buoys at the rear of the Geo Explorer, the larger of two testing vessels, at about 12.30pm from inflatables launched from the MV Greenpeace, to prevent seismic testing.

It added that the activists were remaining in place while testing, which it claims causes climate damage, continues. There were conflicting, unconfirmed reports last night concerning the departure or defiance of the demonstrators.

An AGIP spokesman believed the incident was over by about 5.30pm yesterday evening, claiming the protesters had removed themselves.

The Geo Explorer, and its partner ship the Malene Ostervold, are owned and operated by PGS and are surveying for Agip UK and Phillips Petroleum.

The move against it followed a busy week for the environmental campaign which has protested about other exploration ships, and currently has four protesters in their fourth week of an occupation of the rocky outcrop of Rockall.

Speaking from the MV Greenpeace, Captain Jon Castle said: "This seismic testing is the first phase in the exploration for new oil-oil which we can never afford to burn if the climate is to be saved. The action will continue."

APGS spokesman last night claimed activists had interfered with and damaged equipment deployed by the seismic vessels.

AGIP said the work complied with government environmental and safety requirements.

Phillips declined to comment.

A Northern Constabulary spokesman said it was aware of the situation. "Having sought guidance from the procurator fiscal service, we have been told we have no jurisdiction in this matter but will continue to monitor the situation as it develops."