Britain reduced its terrorism threat assessment to the lowest level for more than five years on Monday.
The threat level was reduced to its third-highest grade, substantial, from severe following “positive developments”, according to the country’s most senior counter-terrorist police officer.
It was raised following a wave of ISIS-inspired attacks on Europe.
Neil Basu said that police had 800 live investigations across the country and 24 plots had been thwarted since March 2017.
The threat assessment was last at substantial in August 2014 before it was raised because of the potential threat of attack linked to wars in Iraq and Syria.
Four people were killed in the European Union in 2014 but the following year 150 were killed and 135 in 2016, according to its policing agency Europol.
Britain had its worst year in 2017 when it was hit by four deadly attacks including the bombing of a pop concert in Manchester in May, which left 22 people dead. Pedestrians on two bridges in London were also targeted.
The threat level rose to its highest level of “critical” for brief periods after the Manchester attack and in September following assessments by independent experts.
“The reduction to ‘substantial’ indicates positive developments in reducing the threat from terrorism but still means an attack is likely,” said Mr Basu. “So it is vital that we all maintain a high level of vigilance and continue to invest in strong protective security measures to deter future attacks.”
More than 500 people across the EU were arrested on suspicion of Islamist related terrorism in 2018, according to the European Union.
The bloc’s security commissioner Julian King warned last week of the continuing threat from returning foreign fighters to the UK and radicalisation of inmates in prisons.
Experts also said there was a danger of retribution attacks by extremists for the death of ISIS leader Abu Bakr al-Baghdadi in a US raid in Syria last month.
