United Kingdom (UK) Prime Minister Keir Starmer said on Monday that a "standing army" of specialist police officers would be established to deal with riots that have rocked the country following deadly stabbings in Southport, northwest England.

Starmer made the announcement after an emergency meeting with ministers and top law enforcement officials after far-right protesters violently clashed with police officers and counter-protesters in many cities and towns of the country in the past week.

The fatal stabbing of three young girls in Southport last week has been seized on by anti-immigrant and anti-Muslim groups, with disinformation spread online and amplified by high-profile far-right figures to spark disorder in towns and cities.

Police say the 17-year-old suspect was born in Britain and that they are not treating it as a terrorist incident. The suspect's parents had moved to Britain from Rwanda.

In the past week, far-right protesters were seen throwing projectiles, attacking officers, looting stores and storming hotels housing asylum seekers in major cities like London, Manchester, Liverpool, Bristol, Leeds, Nottingham and Sunderland, as well as in towns like Middlesbrough, Bolton and Rotherham.

The newest clash took place on Monday evening in Plymouth, a port city in Devon in southwest England, where an anti-migrant demonstration has been met with counter-protesters. Three police officers have reportedly been injured, and a police van has been damaged.

Police have arrested 378 people since the start of the disorder, the UK's National Police Chiefs' Council (NPCC) said on Monday.

NPCC Chair Gavin Stephens said he expects the number to rise daily as police forces continue to identify those involved and continue to apprehend those responsible.

"Violent disorder is a serious offense which often comes with a lengthy jail term," said Stephens.

Following the emergency meeting, Starmer said the government will "ramp up criminal justice" to ensure that "sanctions are swift."

(With input from agencies)