The law aims to spread incidents more evenly out across the evening

Police figures show 67 violent crimes were recorded at licensed premises in the two counties in the 12 months that followed.

In the year ending November 2005, there were 43 incidents. By June this year there had already been 34 cases.

But the Home Office said the increase was not reflected nationwide.

Crimes included murder, attempted murder, manslaughter and wounding.

Sgt Steve Tovagliari, chairman of the Devon and Cornwall branch of the Police Federation, said they warned the Government that extending drinking hours would lead to an increase in violence.

He said: "We said from the outset that extending drinking hours would lead to an increase in violence - that has been borne out."

He said incidents were happening throughout the evening and early morning and officers were having to work longer hours to deal with them.

'No analysis'

The Home Office said the pattern had not been reflected elsewhere in the country and that data collected from 30 police forces in England and Wales showed no indication of an overall rise in the level of violent offences.

A Home Office spokeswoman said it was difficult to attribute levels of crime solely to the Licensing Act.

She said a Home Office report released in July, seemed to confirm the Government's belief that the removal of fixed closing times would reduce incidents overall and spread them more evenly through the night.

"However, as we said on publication of the report, this data does not provide an analysis of the issues," she added.

"As such, it is very difficult to attribute changes in levels of crime and disorder solely to the introduction of the Licensing Act 2003."

Legislation permitting 24-hour drinking was passed in November 2005.