LONDON, Jan. 19 (Xinhua) -- A top British policeman has said that good intelligence is the best way to tackle the threat of terrorism.
"Our best protection is good intelligence. When we know that people are going to hurt people then we arrest them before they get to that point," Metropolitan Police Commissioner Sir Bernard Hogan-Howe told the foreign press based in London at a press briefing Wednesday.
"Our whole strategy is aimed at identifying them and de-radicalizing them, and if we cannot do that we put them before the courts and try to put them in prison," he added.
London's own police service, the Metropolitan Police (Met), is the largest in Britain with about 32,000 officers.
It is also responsible for Britain's Counter Terrorism Command, which operates against the threat of terrorism at a local, national, and international level.
Hogan-Howe is stepping down after five years in the job as the Commissioner of the Met. In this period there was one terrorist attack which have caused deaths in London. The last fatal attack by terrorists in London was in 2013, when a British soldier was murdered outside his barracks in south London.
London's experience is different to that of other capital cities. In the past two years, terrorists have carried out fatal attacks in the Turkish capital city of Istanbul and in several European capitals.
Hogan-Howe said that the threat of similar terror attacks in London and Britain was "severe."
"We have had a threat level of 'severe' for 18 months to two years," he said. This is the second highest threat level, with only "critical" remaining, which would indicate an attack is about to happen.
Hogan-Howe said the Met had "learnt" from the terror attacks in other capital cities.
"We have more physical barriers, where there is a specific event. People will have seen that at New Year we put barriers to prevent vehicles, particularly large vehicles," he said.
The London New Year festivities annually attract crowds of more than 100,000 people. Hogan-Howe said that barriers had also been increased for other popular events, including the annual Notting Hill Carnival, which attracts two million people over three days.
The top policeman said there were especial fears around the 850 British citizens who had gone from Britain to Syria.
Some of these would have gone to fight for extremist groups, he said.
"Of that 850 about half returned fairly quickly, which means there are still around 400-450 there. Our huge concern is that when they return, and... we will have to consider how to deal with that threat," said Hogan-Howe.
Arrests of suspected terrorists in Britain was about one a day on average, with about two thirds of that number in London.
"The main test is whether we can get them convicted in a court," he added.
