Thirty-six people suspected of downloading paedophile pornography from the web have been arrested in raids across the UK.

Police claim this is the tip of the iceberg and they have 2,000 names of offenders they are unable to arrest due to a lack of resources.

Officers from 31 forces searched 44 homes and seized about 30 computers, plus discs and videos.

Operation Ore targeted computer users suspected of accessing US-based websites which sell images of children aged as young as five being sexually abused.

Every image of a child being sexually abused is an image of a crime scene and each photograph is that of a victim

NCIS UK Tactical Services director Vincent Harvey

US authorities gave the National Criminal Intelligence Service (NCIS) the names of 2,000 British subscribers between May 1999 and the summer of 2001.

They were traced by their credit card details which they gave in order to buy the images.

The NCIS' Serious Sex Offenders Unit identified a "significant number" of suspects, and Monday's operation was co-ordinated by the National Crime Squad.

Those arrested ranged in age from 24 to 65.

They include three men - aged 62, 54 and 35 - being held in Merseyside, a 32-year-old man arrested in Scunthorpe and another, 64, arrested in Grimsby, North Lincolnshire,

Sexual abuse

Another man, aged 30, was arrested at an address in Normanton, near Wakefield, West Yorkshire, where two computers were seized for forensic examinations.

Computer equipment was also seized from an address near Rossendale, Lancashire, where a man, 42, was arrested.

In Cwmbran, South Wales, a man in his mid-fifties was arrested with another man. Both were later released on police bail.

Another man, 28, was arrested in Farnham, Surrey.

This is the first time we have targeted people who use the internet to buy images of children being sexually abused

Detective Superintendent Peter Spindler

Police in south west Surrey also arrested a man at his home in Godalming.

A man, 44, from the Sandbach, Cheshire, has also been released on police bail pending further inquiries.

In London, the Metropolitan Police Paedophile Unit also seized computer equipment from two homes in Battersea and Camden.

A man is also being questioned in Crawley, West Sussex.

John Carr, internet consultant for children's charity NCH, is concerned about the 2,000 people at large.

Dangers

He told BBC News: "We think it's very important that the police are given whatever resources are necessary to sweep up the rest of them."

Deputy Assistant Commissioner and Association of Chief Police Officers (Acpo) spokeswoman on internet child abuse, Carole Howlett, said: "A significant proportion of people involved in child abuse online are themselves actual abusers."

NCIS UK Tactical Services director Vincent Harvey added: "Every image of a child being sexually abused is an image of a crime scene and each photograph is that of a victim.

"Using the sophisticated technology along with traditional detective and analytical work, we can now make sure there is no place for paedophiles operating online to hide."

The government is determined to give the highest priority to protecting our children, on and off-line

Home Office minister Beverley Hughes

The National Crime Squad's Detective Superintendent Peter Spindler said: "This is the first time we have targeted people who use the internet to buy images of children being sexually abused.

"We will continue these operations to protect children and show paedophiles that law enforcement agencies will find them regardless of which area of the internet they use."

Home Office minister Beverley Hughes, who chairs the government's task force on child protection on the internet, said the operation sent "a clear signal to such criminals that they cannot hide".

"People who access child pornography are fuelling the widespread and often organised sexual abuse of children by paedophiles across the world."