No-one has been charged in connection with the alleged protest plan
Police have defended their decision to arrest 114 environmental campaigners in connection with a suspected plan to protest at a power station.
The men and women were held in Sneinton Dale, Nottingham, on Monday and later released on bail.
Police said they had been planning to cause "prolonged disruption" at Ratcliffe-On-Soar power station.
Meanwhile, the BBC has found the station's owner E.On had already warned its staff about possible protests.
No-one has been charged in relation to the case.
In a letter sent to around 17,000 staff employed nationally by E.On last month, the company's chief executive said protesters had already tried to shut down power stations and get access to the firm's offices over controversial plans for the company's new Kingsnorth coal-powered station.
Staff were also sent a leaflet offering personal safety advice and telling them how to handle possible encounters with protesters.
More than 200 officers from Nottinghamshire, Derbyshire, Leicestershire, Staffordshire and British Transport Police took part in the raid at the Iona School in Sneinton shortly after midnight on Monday.
Supt Mike Manley of Nottinghamshire Police said large amounts of equipment had been found, including food and various devices used for climbing, cutting and locking on to machinery.
He said: "We think it was a sophisticated attempt to disrupt what we now believe was Radcliffe-on-Soar Power Station...
"Our information was that it wasn't to be a lawful protest. This was to be a criminal act against a power station.
"Had that taken place, we would have now been policing a major protest at a major power station."
There were no reported injuries and local residents said handcuffed suspects sang loudly as they were led away.
No-one has been charged with any offence.
The scale of it makes people think we are dealing with a major terrorist incident
Nottingham South MP Alan Simpson
On Tuesday the nursery at Iona School was closed while workmen repaired doors damaged in the raid.
The school said it was distressed at the disruption and damage caused, and the group had had no permission or authority to meet there.
Officers also said that some of those arrested had links to climate change groups which had protested at Kingsnorth power station in Kent, Heathrow Airport and Drax power station in north Yorkshire.
However, police would not name any organisations.
Nottingham South MP Alan Simpson raised concerns over the nature of the policing operation.
"The scale of it makes people think we are dealing with a major terrorist incident," he said.
The power plant, which is eight miles south-west of Nottingham, has seen protests by environmental campaigners in the past, including members of Eastside Climate Action.
Bob Andrews, from the group, denied any connection with the latest incident.
However, he said direct action was the only way to bring about a change in energy policy.
He said: "We're saying we've got to change policy, and (the government and E.On) are not doing it.
"They're not taking the science seriously. It's got to change. Stop burning fossil fuel."
David Porter, chief executive of the Association of Electricity Producers, said campaigners' calls to stop burning fossil fuels made no sense.
"If you suddenly close down our power stations that would be a suicidal policy.
"The economy of the UK would be seriously disrupted. And there would be social implications of that.
"It's a nonsensical approach to the problem."
The protesters are suspected of plotting to break into Ratcliffe-on-Soar Power Station
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