The Prime Minister has told his third emergency Cobra meeting since violence broke out last week that police need to remain on “high alert”, the PA news agency understands.

Sir Keir Starmer is understood to have said there is no doubt that levels of policing in the right places and swift justice over the past week, including sentencing, have acted as a deterrent to disorder.

He also thanked the police and wider criminal justice system at the meeting.

The Prime Minister had earlier insisted it was “important that we don’t let up”.

Anticipation of more disorder largely failed to materialise on Wednesday, but the National Police Chiefs’ Council (NPCC) has warned that 20 potential gatherings and three counter-protests were believed to have been planned for Thursday evening.

NPCC chairman Gavin Stephens told reporters earlier that those “intent on violence and destruction have not gone away” as he said police were “very focused on the weekend”.

He suggested police patrols could be stepped up at lower league matches at the start of the football season amid concerns there could be flare-ups at forthcoming fixtures.

While perpetrators had been “deterred” and “received a message from communities”, there are “many potential events still being advertised and circulated online”, he said, adding: “There’s no complacency at all in our mind that we need to be prepared for the days and particularly the weekend ahead. So the policing posture remains the same.”

Some rioters have already been jailed for up to three years, as other suspects continue to face court over disorder across the country.

A 55-year-old woman from near Cheshire was arrested on Thursday in relation to a social media post containing inaccurate information about the identity of the suspect in the Southport murders.

Cheshire Police Chief Superintendent Alison Ross said: “It’s a stark reminder of the dangers of posting information on social media platforms without checking the accuracy.

“It also acts as a warning that we are all accountable for our actions, whether that be online or in person.”

The total number of arrests made after violence erupted in the wake of the Southport stabbings now stands at 483, with 151 charges brought so far.

The figures are expected to “continue to rise significantly”, the NPCC said.

More than 160 demonstrations were planned for Wednesday but only about 36 took place with “minimal disorder and only a handful of arrests”, according to police chiefs.

Fears of midweek riots after the days of disorder saw shops boarded up and staff told to work from home where possible in towns and cities anticipating more trouble.

Large numbers of people instead gathered in areas including Walthamstow in east London, Bristol, Brighton, Liverpool and Sheffield to take part in counter-demonstrations.

Stand Up to Racism claimed an estimated 25,000 people took to the streets to show they were against racism and violence.

Nick Emmerson, of the Law Society of England and Wales, said the threats purporting to target immigration law firms were an “attack on our democratic values”.

Counter protesters demonstrating in Brentford, London
Counter-protests took place on Wednesday night (PA)

Mr Stephens described what actually unfolded as a “turning point”, but admitted being “nervous” beforehand, adding: “I think what we saw last night was a loud and clear message from communities that they’d had enough, that there’s no place for hate, that there’s no place for violence.”

The cost of damage to neighbourhoods caught up in the violence was “going to take a long, long time to recover”, he warned.

Cleveland Police Chief Constable Mark Webster said the riots had cost the region an estimated £300,000.

The Prime Minister told broadcasters during a visit to a Solihull mosque that Wednesday night’s events turned out “much better than was expected”.

Sir Keir said: “We were able to demonstrate the criminal justice system working speedily, so yesterday we saw the sentencing of individuals who had been involved in disorder days ago, some of them getting sentences as long as three years.

“That sent a very powerful message.”

In the West Midlands, the Prime Minister also met Justice Secretary Shabana Mahmood, West Midlands Mayor Richard Parker, Muslim residents and police officers who attended some of the violent clashes.

Metropolitan Police chief Sir Mark Rowley had earlier suggested the “show of force from the police” and “the show of unity from communities” together “defeated the challenges that we’ve seen”.

Metropolitan Police Commissioner Sir Mark Rowley
Metropolitan Police Commissioner Sir Mark Rowley (Aaron Chown/PA)

He also told the BBC his force had carried out dawn raids as they hunt for the most violent perpetrators of the disorder seen in Whitehall last week, about 70% of whom he said had criminal backgrounds.

“We’ve got criminal damage, violence, weapons offences, football banning orders. These are criminal thugs,” Sir Mark said.

At least 191 police officers are thought to have been assaulted so far in the unrest, resulting in 100 being injured and 66 being taken to hospital, PA understands.

These are the latest known figures on officer injuries from 29 out of the 43 forces in England and Wales, according to police sources. The total number of officers injured across all forces is not yet known.

Many police officers had sustained injuries including “fractures, lesions and severe bruising” amid the at times “brutal and ferocious” unrest, Mr Stephens said.

Rehabilitation and psychological support will be offered to officers because “for many, it was absolutely terrifying”, he added.

Mr Stephens also made a plea to children not to ruin their lives by getting drawn into the disorder, as figures compiled by PA showed 17 people aged 17 or under had so far been charged with related offences.