Police are facing criticism over their "heavy-handed" approach to clearing barricades at the UK's largest illegal Travellers' site.
Clashes between police and protesters continued at Dale Farm last night after a morning of violent confrontations in which two people were shot with Tasers.
The law reform group Justice expressed concern at the use of the weapons, but police said officers had been threatened with "serious violence".
Police said they had secured the area and removed protesters from a 40ft-high scaffolding tower which had been erected at the main gate to the site. A total of 23 arrests were made throughout the day. "We are in control of the whole site. It is calm.
The tension is now reduced," said Superintendent Trevor Roe, of Essex Police.
Police broke down a fence at the back of the site, and protesters pelted them with bricks, bottles and other debris and built barricades. An unoccupied caravan was set alight and two explosions were heard as it burned. No one was hurt.
Supt Roe said the two officers who fired Tasers had been trying "to protect themselves".
He said: "They carry personal protective equipment which includes the Taser and they just naturally reacted as they are trained individuals to operate that device."
Acknowledging that the use of Tasers is not recommended as a "public order tactic", he added: "This was an isolated incident where officers were threatened directly."
Supt Roe continued: "The first officers on the site were attacked with missiles being thrown, including rocks and liquids. These officers were fully equipped to deal with this situation."
He said police had gone into the site as Basildon Council was worried that violence would break out once the clearance began.
Residents and protesters accused them of being heavy handed and of carrying out the eviction on behalf of bailiffs. "I have been through a lot of evictions but I have never seen anything like this.
"To see riot police on our doorsteps is shocking. We are terrified of the police," said Kathleen McCarthy, who lived at Dale Farm.
The clearances mark the climax of a 10-year legal battle between the council and the community. The residents had won a last-minute injunction as bailiffs massed at the gates, but a High Court judge ruled this week that the clearances could go ahead.
At least 50 officers led the operation to clear the site, and at least one person was taken to hospital. Basildon Council officials now estimate the cost of the eviction could rise to £18m.
Tony Ball, leader of Basildon Council, condemned the violence. He said: "The premeditated and organised scenes of violence that we have already seen, with protesters throwing rocks and bricks, threatening police with iron bars and setting fire to a caravan, are shocking.
"These are utterly disgraceful scenes and demonstrate the fact some so-called supporters were always intent on violence. Nonetheless we are going to press on with this operation with our partners in a safe, dignified and humane way and will uphold the law."
Guidance on the use of Tasers issued by Acpo in 2008 says it is "not possible to provide a definitive list of circumstances where the use of Taser would be appropriate".
But Acpo recommends that police should not use the weapon as a way of restoring public order.
Tasers: When should they be used?
The use of Tasers by police divides opinion. Human rights groups claim they are "potentially lethal", and responsible for hundreds of deaths in the United States, while the Association of Chief Police Officers says they have a significant deterrent effect.
In 2008, 10,000 Tasers were issued to police. They fire two electric barbs up to 35 feet and deliver a disabling, 50,000-volt shock, which can penetrate clothing up to two inches thick.
In a memorable video, the Chief Constable of North Wales, Richard Brunstrom, screamed as he was stung by a Taser in a training situation.
The police remain acutely sensitive to public doubts about the Taser. The Independent Police Complaints Commission recently introduced rules making officers forward all complaints about Tasers to the police watchdog.
A US police expert, Lieutenant Todd Faulkner, said earlier this year that the Taser should never be deployed during "a dynamic, deadly force situation". It was just such a situation in which the fugitive Raoul Moat was shot with a Taser by Northumbria Police. Last year the manufacturer, Taser International, warned against firing the weapons at anyone's chest area because of "the controversy about whether or not" they might cause harm.
Dale Farm history
1960s At a scrapyard in Essex, part of the wider Dale Farm, a handful of Travellers began to arrive and settle, forming a small site that was authorised by Basildon Council.
2001 As the site grows, Traveller families set up pitches adjacent to the authorised site, but which are illegally on green belt land.
2005 Travellers are ordered to leave Dale Farm in May after a planning inspector declares the development illegal.
2006 Dale Farm Travellers hold a vigil in Whitehall.
2007 Basildon Council hires eviction specialists to bulldoze the site.
2009 Basildon Council's decision to evict is quashed in the High Court, but this ruling is subsequently overturned on appeal.
2011 Eviction notices are served by the council in July, giving residents occupying 51 unauthorised pitches 28 days to vacate the land.
19 September Bailiffs arrive at the main gate of Dale Farm to start the eviction of up to 80 families living on the unauthorised plot. But residents win a last-gasp injunction.
17 October Residents refused permission to appeal against a High Court ruling that gave Basildon Council the go-ahead to evict them.
19 October Bailiffs and riot police clash with protesters as they arrive to clear the site.