Incidents of violence and abuse against ambulance crews trebled in a year, with the majority of cases due to late-night drunkeness of victims and bystanders.

Paramedics are often left frightened and severely shocked by the levels of abuse they receive as they go to the aid of injured people.

The escalating levels violence have led to crews being trained in self-defence, and many victims of alcohol and drug-fuelled fights are now treated with suspicion by ambulance staff.

In the latest Department of Health figures available for West Yorkshire, incidents shot up from 65 in 2001-2002 to 183 assaults a year later.

Over the same period nationally, assaults leapt from 4,778 to 5,283, up 10.5 per cent.

In the wake of those figures, the government set up a new system of reporting violent incidents against ambulance crews to get a more accurate picture.

Now a full Government report into the audited figures of attacks on paramedics is due to be published before the end of the summer. Health Minister Jane Kennedy said the previous Department of Health figures were "estimates" provided by

each ambulance service.

She said an NHS Security Management Service (SMS) was set up to tackle violence against health workers and a new national reporting system for assaults was introduced in November 2003.

She said: "The SMS has begun a programme of work to identify the true nature, scale and extent of the problem of violence against NHS staff.

"Accurate information concerning physical assaults against NHS staff is expected to be available from summer 2005."

In September last year, the Telegraph & Argus launched its End The Abuse campaign to cut the levels of violence against NHS staff by patients after it was revealed incidents of aggression against NHS staff in Bradford have doubled in just six years.

At Bradford Royal Infirmary and St Luke's Hospital, some 70 staff a month suffer violence or intimidation by patients or their families.

Doctors, nurses and auxiliary staff have been punched, threatened with broken bottles, had computers and mobile phones thrown at them and witnessed vandalism against hospital equipment.

Andrew Simpson, WYMAS group station manager in Bradford, who has been a paramedic for 20 years, has been the victim of verbal and physical abuse on a number of occasions.

He said: "The after-effects, when you get home, can be quite severe. You're left feeling shocked and suspicious when working with people.

"On one occasion a car driver refused to let an ambulance with blue lights flashing and sirens pass at a narrow bridge and when he eventually did give way the driver shouted abuse at the crew."

Many incidents were alcohol-fuelled and often involved crews attending calls to fights on Friday and Saturday nights and then receiving abuse from the patient or people looking on.

WYMAS has installed panic buttons and satellite tracking systems, and paramedics are being given self-defence lessons to tackle the growing levels of violence.

Panic buttons are on all radio handsets and ambulances which send a signal sent to a central control to summon assistance.

All crews also carry mobile phones and vehicles can be tracked by satellite tracking systems.

The self-defence training involves communication skills, body language and breakaway techniques, and advice on how to deal with abusive people.

Ambulance bosses say the high expectations of patients and the use of drugs and alcohol is the main reason for abuse against paramedics.

Geoff Langstaff, assistant director of operations and head of clinical services at WYMAS, said: "It is sad it has got to this stage but I have seen an increase over the years.

"You would never have considered that as an NHS worker you would be putting your life at risk but unfortunately these incidents occur."