Nurses and other frontline health workers are facing increasing threats of violence across the country, with many assaults going unreported, it was revealed today.

Unison called for a tough new campaign of zero tolerance and said people who attacked or threatened health staff should face stronger penalties.

The union obtained new figures which showed there were almost 59,000 physical assaults on NHS staff between 2005 and 2006 in England alone.

The highest number of assaults were in London at 5,700 followed by West Yorkshire and Trent which both reported more than 3,600 incidents.

Unison's head of health Karen Jennings said: "It is a disgrace that nurses, paramedics and healthcare workers should face the threat of violence for trying to do their job, caring for people sick or in pain.

"Sadly these figures are likely to be just the tip of the iceberg as many assaults still go unreported.

"Unison is particularly concerned at the growing problem of aggression from visitors to frontline staff such as bedside nurses working in high dependency, coronary care and intensive care units.

"Nursing staff in these units are exposed longer to abuse because they cannot walk away and leave patients uncared for."

Unison said it was concerned at the psychological trauma suffered by nursing staff who were already working in a highly stressful environment.

The figures were published at Unison's health workers conference in Brighton today where delegates made it clear that verbal abuse and aggression should not be tolerated.

One union official said some accident and emergency centres were like "war zones" and assaults on staff were just as terrifying for other patients waiting to be treated.

The total number of assaults in England went down slightly compared to the previous year, but in many areas there was an increase in incidents including Norfolk, Suffolk and Cambridgeshire, Bedfordshire and Hertfordshire, parts of London, Cheshire and Merseyside, Hampshire and Isle of Wight, South West Peninsula, Dorset and Somerset, South Yorkshire, Leicestershire, Northamptonshire and Rutland, Shropshire and Staffordshire and West Midlands South.

Unison obtained the figures in a Parliamentary question to the Government.