A SENIOR London police officer has said the force regards IRA ceasefires as "periods of preparation" for further violence.

Mr David Vaness, assistant commissioner of the Metropolitan Police, said the Docklands bomb in London in February "marked the end of the last period of preparation which some people call a ceasefire".

He told a conference in Dublin that the police force is "resigned to the long-term threat of the Provisional IRA". "We regard ceasefires, sadly, as periods of terrorist preparation, although we wish God speed to all of those, particularly politically, who seek to bring about such phases."

Mr Vaness was speaking at the conference, entitled "International Perspectives on Crime, Justice and Public Order", which concluded at Dublin Castle yesterday.

Speaking after addressing the conference, Mr Vaness said the force would "warmly welcome and encourage" efforts to promote a ceasefire, but warned: "Periods which are labelled ceasefire may be in the future, as in the past, periods of preparation." He said that was the "harsh reality" of the last IRA ceasefire and security forces had to approach ceasefires from that perspective.

Mr Vaness told delegates one growth area in criminal activity has been kidnapping, particularly of tourists and aid workers overseas. He said "adventure holidays" had increased the number of people going to "risky but irresistible" countries, without being aware of the dangers.

Almost every day for the last two years the Metropolitan Police of Britons abroad, he said.

Such crimes brought increased co-operation between national police forces. He said the media had made coping with such crimes more difficult, because modern communications meant "real time" coverage of events, while there was also increasing competition among news organisations.

He added that on some occasions, reporting had been "grossly irresponsible, contrary to the interests of law enforcement and, at times, life threatening".

During yesterday's closing session, the delegates also heard from a New York public prosecutor about an expected growth in the criminal population of the US.

Mr Robert Johnson, district attorney for Bronx County, said studies had shown the number of people in the youth age-bracket rise by 500,000 by 2000 and by between 4.5 and 5 million by 2010. Six per cent of this age group was considered likely to turn to crime, which would mean 30,000 extra criminals by 2000 and 270,000 by 2010.

Mr Johnson said he was keen to encourage programmes which taught young people the real cost of crime, particularly drug-related crime.

In the Bronx there were schemes which brought school children to hospitals to "view the effect of crack first-hand - they see babies born crack-addicted," he said. There was also a programme requiring school children to visit courtrooms so that they could see drug dealers being sentenced to jail terms.

Meanwhile, money seized from dealers was used to fund "mediation programmes" in the schools, to teach children how to resolve disputes without violence.

Mr Johnson said the best people to promote such schemes were those working in the law enforcement area. Suggestions from social services employees were often ignored, whereas police and law officials who were "tough on crime" could use their political credibility to push for such schemes.

"I believe that's the way we're going to have to go in terms of causing a reduction in crime in the long term," he said.