More than 200 terrorist attacks took place, were foiled or failed in Europe last year, an official report has found.
Over half of the cases were recorded in the UK, according to figures compiled by Europol.
Nine member states reported a total of 205 terrorist attacks that were either stopped, failed or completed, the EU's law enforcement agency said - up from 142 in 2016.
The UK experienced the highest number with 107, which includes 88 security-related incidents in Northern Ireland, the EU terrorism situation and trend report said.
It comes after Londoners fell silent yesterday to honour the victims of the Finsbury Park terror attack one year after Darren Osborne ploughed a van into a crowd of Muslims as they left a mosque during Ramadan.
France recorded the second largest number, with 54, followed by Spain (16), Italy (14), and Greece (8).
Researchers said attacks in EU countries killed 68 victims and left 844 injured last year, with nearly all the reported fatalities and casualties resulting from jihadist atrocities.
The number of jihadist terrorist attacks increased from 13 in 2016 to 33 in 2017, while ethno-nationalist and separatist attacks accounted for the largest proportion of the incidents, with 137.
The report said the violent right-wing extremist spectrum is expanding, "partly fuelled by fears of a perceived Islamisation of society and anxiety over migration".
The failed, foiled and completed attacks on the EU in 2017
United Kingdom - 107
France - 54
Spain - 16
Italy - 14
Greece - 8
Belgium - 2
Germany - 2
Sweden - 1
Finland - 1
Five foiled, failed or completed attacks attributed to right-wing extremism were reported - all of them by the UK.
On Islamic State, the assessment said the degradation of the group's organisational structures may reduce its attractiveness.
But it warned that this may not affect the threat of jihadist terrorism, noting that disaffected IS members and sympathisers could be drawn to other groups such as al Qaida.
By 2017 more than 150 social media platforms were identified as being abused by terrorists for propaganda dissemination, according to the paper.
It said: "Online propaganda continues to be an essential part of jihadist terrorist attempts to reach out to EU audiences for recruitment, radicalisation and fundraising."
While the outflow of individuals travelling from the EU to fight with terrorist groups has slowed, Europol underlined that IS, al Qaida and other jihadist groups continue to pose a major threat.
British European commissioner for security Sir Julian King said the report shows Europe continues to be a target for terrorism.
He said: "We need to keep our collective eye on the ball, and strengthen our efforts at EU level to deny terrorists the means they need to carry out attacks including arms, explosives and funding; work on evolving areas such as CBRN (Chemical, Biological, Radiological and Nuclear) threats; and continue to tackle radicalisation and all types of violent extremism."
Europol executive director Catherine De Bolle said: "The numbers in this report are not just statistics. We must never forget that behind every number, there is an innocent victim."