LONDON - Police officers in Britain were subjected to almost 2.5 million assaults over a 12 month period, the Police Federation said in a report released Sunday.

The federation, regarded as the trade union for police officers, said the new figures reveal the horrific extent and frequency of assaults on police officers.

Estimations based on data from a welfare survey data suggest that there were potentially more than two million (2,113,602) unarmed physical assaults on officers over a 12-month period, and a further 302,842 assaults using a deadly weapon during the same period.

It means there were a total of 2,416,445 attacks, 40,009 injuries due to violence, equating to a policeman or policewoman being assaulted at the rate of one every four minutes.

Until now the estimate had been that around 23,000 police officers were assaulted every year, but the new figures presented a stark reality of the job and what police officers have to deal with.

A spokesman for the federation said: "It has been difficult to determine the actual number of police officers assaulted every year. Much of this has been down to what data has been used, taking into consideration inconsistencies and a variety of recording processes."

"Incidents are also often under-reported, further contributing to an incomplete national picture on what is a growing concern," the spokesman said.

Steve White, the federation's chairman for England and Wales said: "We always knew that 23,000, whilst bad enough, was not the true picture but 2.4 million is beyond anyone's expectations and totally unacceptable."

Last year the federation raised the issue with Britain's interior department, the Home Office, about the official figures not giving a true picture of the number of police assaults per year.