Police across Britain have been put on high alert warning that they may be targeted in terror attacks following the foiled assault on officers in Belgium this week by Islamists with links to Syria.

The threat against police has been raised to severe, the highest level yet, with police chiefs considering the more widespread deployment of Taser stun guns as an additional security measure.

Police patrols of Jewish communities in Britain are also to be stepped up amid “heightened concern” about the risk of an attack following the Paris atrocity, Britain’s top counter-terror officer said. Extra security measures will be taken at Jewish schools.

In Washington, where he was discussing the terror threat with President Obama, David Cameron said it was important to learn the lessons of the past 10 days.

“The government has a very strong relationship with the Jewish community; it talks to them regularly about these issues. We have to be incredibly vigilant and look at all of these risks, particularly risks to police officers themselves, and take every action that we can.”

A further 15 arrests were made across Belgium after two men were left dead following a shootout on Thursday in Verviers. Officials said among items recovered from raids were police uniforms and radios – suggesting a sophisticated level of planning and determination to kill police.

The threat of officers being targeted by a terrorist in Britain was raised to substantial in October, and on Friday was elevated further to severe, meaning an attack on a police officer is highly likely. It is the fourth highest of five levels and follows an assessment by the Joint Terrorism Analysis Centre based within MI5.

The plans to more widely deploy Tasers, which deliver electric shocks, are at an early stage but could see more officers trained to use the weapons out on patrol. British police are mostly unarmed, unlike colleagues in France and Belgium, and firearms are comparatively rare on Britain’s streets. It is thought terrorists would be more likely to use knives or machetes to attack an officer, rather than guns, in a rerun of the gruesome attack on soldier Lee Rigby in May 2013 near his barracks in Woolwich, south London.

One source said: “We are at the maximum point of awareness before something happens.”

Other measures open to police chiefs in the 44 forces that patrol the streets across England and Wales include many more officers going out in pairs, or “proximity” patrols, where colleagues are never out of sight of each other.

Last weekend Islamic State propaganda renewed a call for followers to attack the police. New York City police has already issued urgent safety advice to officers to watch the hands of anyone approaching them, and other measures.

The alert to police in Britain was announced by the national policing lead for counter-terrorism, Assistant Commissioner Mark Rowley, who said: “We are also considering what further measures we might put in place to enhance the security of police officers, given some of the deliberate targeting of the police we have seen in a number of countries across Europe and the world. Chief constables across the country are reviewing how to strengthen the protection of their officers from such attacks.”

Steve White, chair of the Police Federation of England and Wales, said: “The level of extreme terrorism we are facing on an international scale cannot be underestimated and the police service and its security partners are doing all they can.

“Police officers face life-threatening risks on a daily basis and are prepared to do so fully aware of the risks involved. As a service we are regularly assessing what we do in order to adapt to the changing and challenging issues we face.”

Rowley said there would be extra patrols in Jewish areas amid fears they will be targeted as were shoppers in a kosher shop in Paris last Friday, leaving four people dead.

Jewish communities across Britain have already increased their own patrols amid high levels of anxiety. Posters advertising a Holocaust memorial event in East London were yesterday daubed with graffiti including the words “liars” and “killers”. The Metropolitan Police said the incidents, which took place in Stratford, were being listed as a “hate crime”, and said officers in Newham were investigating.

Rowley said: “The global picture of terrorist activity does give us heightened concern about the risk to the Jewish community in the UK. We are seeing continuing anti-Semitic rhetoric from extremists and attacks on this community in France and elsewhere.

“In addition to our existing security measures, we are in dialogue with Jewish Community leaders about further actions that we will be taking, including more patrols in key areas.”

Mark Gardner, director of communications at Community Safety Trust, which works with police to keep Jews in Britain safe, said : “We have taken an unprecedented number of calls and emails from concerned members of our community from parents of school children to shop owners and all manner of organisations.

“The concern is people have heard the way the Government and police talk about the current level of terrorism threat to the UK as a whole, then they see what happened in Paris and they are reminded in the harshest possible way that such an attack could of course happen here.”