Fifty police officers across Britain have been arrested as part of a crackdown on suspected paedophiles who pay to access child pornography websites, detectives revealed today. The officers were among 1,300 people arrested on suspicion of accessing or downloading indecent images of children - some as young as five - from US-based Internet sites. Thirty-four men were arrested in London this morning as part of the investigation - codenamed Operation Ore - following raids on 45 addresses across the capital. In addition, 40 children nationwide - 28 of them in London - had been identified as being at risk of being abused and appropriate steps had been taken with other agencies to ensure that all the youngsters were safe. Before today's arrests, the Metropolitan Police had executed 75 warrants across the capital with 65 arrests and more than 130 computers seized. The Met's Deputy Assistant Commissioner, Carole Howlett, said today's raids represented the single largest operation of its kind mounted so far by the force. Operation Ore is the UK wing of a huge FBI operation which traced 250,000 paedophiles worldwide last year through credit card details used to pay for downloading child porn. The names of British suspects were passed on by US investigators.