Two pensioners have vowed to continue protesting over the controversial cutting down of trees despite being arrested and spending eight hours in a police cell when contractors and police descended on their street in a "dawn raid".

Retired sociology professor Jenny Hockey, 70, and her friend, retired teacher Freda Brayshaw, 71, were arrested on Rustlings Road, Sheffield, in an operation former deputy prime minister Nick Clegg described as being more akin to a well-planned anti-terror raid than a morning of tree-felling.

Mr Clegg, who is the local Liberal Democrat MP, demanded answers from council officials and senior police officers, saying: "I don't know what planet these people are on."

Angry Rustlings Road residents said they were woken at about 5am on Thursday by workers from Sheffield City Council's contractors Amey, who were accompanied by a large number of police officers.

They said the officers banged on their doors and demanded cars were moved immediately or they would be towed.

Mrs Hockey said she was shocked to find police at her door.

She said: "There were two police officers on the doorstep so I instantly thought something terrible had happened to my kids.

"Then I thought somebody had nicked the car. I didn't realise they were about to, as it were, take the car."

Mrs Hockey said: "The street was seething with people - lights, noise, chainsaws. The whole thing was just horrific."

She said she was arrested outside her home when she refused to leave the base of the tree.

"What can you do in that situation except exercise your right to peaceful protest and that's what we chose to do," she said.

"They warned us they'd arrest us if we didn't move, which is what they did."

"It's devastation," she said. "These are healthy trees. These are extremely valuable trees."

Mrs Brayshaw said: "It was just like an assault with arc lights, lots of police men and Amey men and chainsaws going up and down the road and we had no chance to do anything.

"All we were doing was exercising our democratic right to protest. They had a kind of barrier, a tape around trees they intended to fell and I stepped inside and stood under a tree. That's it."

A 35-year-old man was also arrested and also released later.

The teams of tree surgeons aimed to cut down eight trees - mostly limes - and managed to fell seven.

After a stand-off, contractors began to cut down the final condemned tree, at one point chopping branches from a cherry-picker directly above the heads of residents who had gathered underneath.

But when campaigner Jason Leman stood next to the trunk and refused to move, just before torrential rain set in, the work was abandoned for the day.

The operation and resulting protest is the latest drama in a long-running dispute over the plan by the council and Amey to fell trees across the city, which has gone all the way to the High Court.

Council bosses say the programme is essential if Sheffield's 36,000 street trees are to be managed for future generations.

They say trees scheduled for felling are dying or diseased, or pose dangers.

Mr Clegg arrived on the scene and told residents: "Do you seriously plan a dawn raid for trees? It's treating residents like an anti-terrorist operation.

"I don't know what planet these people are on."

The Sheffield Hallam MP said: "I'm outraged. It's boneheaded, it's stubborn, it's disrespectful, it's very alarming. Arresting elderly residents? Arresting them when they're just trying to say 'don't chop this tree down'?"

Mr Clegg said many of the trees did not need to be felled but it was cheaper for Amey to chop them down rather than repave all the pavements.

"This has got to end, this is really getting out of hand," he told residents at the remaining tree.

"I am absolutely gobsmacked and furious on your behalf."

In a statement, Bryan Lodge, the council's cabinet member for the environment, said he stood by the decision to do the "vital" maintenance work.

Mr Lodge said: "For more than a year we have worked tirelessly with Amey and the local community to find the right solution for Rustlings Road.

"We have written to every home, brought in a new survey process for the entire city and set up an independent tree panel.

"Our approach has been assessed at the High Court on three occasions.

"We have made a final decision to increase the number of trees on Rustlings Road by almost 30%.

"We need to replace eight out of the 30 existing trees, but we will plant 17, which means the road is gaining an extra nine trees.

"We understand that this will be a difficult day for the tree campaigners, but this work is absolutely essential to ensure that Sheffield has healthy street trees for future generations.

"We carried out the work very early in the morning, on the advice of the police, to make sure it could be done safely. This isn't usually needed but in this case it was considered the best option for the safety of the public, protesters and the workers.

"I understand there are strong emotions about this but have to stand by the decision to do this vital maintenance work. We've got 36,000 street trees in Sheffield and this programme means that in years to come we'll have even more."

South Yorkshire Police confirmed that 12 officers "provided assistance at the request of the council".

A police spokesman said: "We have a small presence to ensure the safety of local residents and contractors whilst the work is carried out.

"Three people have been arrested on suspicion of preventing lawful work under Section 241 of the Trade Union and Relation Act 1992."