A petrol bomb attack on an immigration centre in Britain was motivated by far-right "terrorist ideology", police have said.
Counter-terrorism police said they found evidence on digital devices that there was "an extreme right wing motivation behind the attack".
The suspect, named by police as 66-year-old Andrew Leak, is also believed to have had mental health problems.
He was found dead at a petrol station after the attack on the Western Jet Foil centre last Sunday, in which two people were injured.
The government had initially said the attack in Dover, at England's south-eastern tip, was not being treated as a terrorist incident.
But counter-terrorism police said in a statement on Saturday that the threshold for declaring a terrorist incident had since been met.
“Whilst there are strong indications that mental health was likely a factor, I am satisfied that the suspect’s actions were primarily driven by an extremist ideology,” said counter-terrorism co-ordinator Tim Jacques.
“Increasingly in counter terrorism casework, across all ideologies, we are seeing individuals who have mental health concerns and a hateful mindset.”
The incident was one of several flashpoints in recent days amid a bitter debate over immigration and asylum.
Separately on Saturday, police reported a disturbance at the Harmondsworth immigration centre in London following a power cut overnight.
The Manston centre was also in the spotlight as Home Secretary Suella Braverman came under pressure over conditions there.
It comes against the backdrop of small boat journeys across the English Channel, attempted by at least 38,000 people this year, which Ms Braverman has promised to stamp out.
Dover lies at the narrowest point of the Channel, only 33 kilometres from France, and some arrivals are accommodated at the Western Jet Foil centre.
The suspect in the October 30 incident attacked the site with "a number of crude incendiary devices" and is believed to have acted alone, police said.
Police recovered the electronic devices during a search in High Wycombe, where Mr Leak lived.
A bomb disposal unit was dispatched to Western Jet Foil after the attack. Police said there was no wider threat to the public.
Opposition politicians have accused ministers of playing with fire with their rhetoric, such as Ms Braverman's reference to a migrant "invasion".
But Ms Braverman said after visiting Dover and Manston that efforts would continue to make Channel crossings unviable.
The government published figures on Thursday showing a rise in Albanian migrants, in support of its claims that many of those seeking asylum do not need it.
That led to a stinging retort from Albania's Prime Minister Edi Rama, who said the UK should "stop discriminating against Albanians to excuse policy failures".
This is a developing story
