The vulnerability of shopping centres to terror threats is echoed in a report published this week warning that Islamic extremists are "highly likely" to mount terror attacks at the games next year.
He was more emphatic in attributing blame for the Salisbury attack than Theresa May, who has tended to speak of Russia rather than the Kremlin and who has restricted her assessment to saying only that Russia is "highly likely" to have been behind the attack.
Earlier on Tuesday, David Cameron said the government did not think it necessary to raise the terror threat level in the UK from severe, which means an attack is "highly likely", to critical, which suggests an imminent threat.
The formula that the EU is taking "extremely seriously" the UK's assessment that Russia was "highly likely" to be responsible for the Salisbury attack is not quite a full endorsement of the British government's position.
We are confident in our own assessment that the Syrian regime was highly likely responsible for this attack and that its persistent pattern of behaviour meant that it was highly likely to continue using chemical weapons.
"It's highly likely that similar attacks leveraging those types of credentials could follow in addition to a continued Google attack vector.
Fortinet's FortiGuard Labs' security strategist Richard Henderson tells TechCrunch that "As with many high-profile social media breaches in recent years, it's highly likely this attack was the result of a targeted spear phishing attack in order to capture social media credentials or deliver malware that provided remote access".
The National Cyber Security Centre [NCSC] has said it was "highly likely" the attack was carried out by a North Korea cyber organisation known as the Lazarus Group.
In March 2009, the BBC revealed that MI5 had increased the official threat assessment level posed by dissident groups to severe, meaning an attack was regarded as "highly likely", whereas previously an attack had been regarded as "a strong possibility".
This means a terrorist attack is "highly likely", according to the official grading system and comes despite the overall threat level to the UK being downgraded earlier this month.
Security expert Graham Cluley, from anti-virus firm Sophos, said it was highly likely the attacks originated from Android devices, given all available information, but this could not be proven.
