A terrible reminder, says MI5 boss
The terrorist attack at the offices of Charlie Hebdo magazine in Paris was a "terrible reminder of the intentions of those who wish us harm", the head of MI5 has said.
Ahead of a speech in London tonight, Andrew Parker, director general of the Security Service, said MI5 would be offering its French counterparts its "full support".
Mr Parker said: "It is too early for us to come to judgments about the precise details or origin of the attack but it is a terrible reminder of the intentions of those who wish us harm.
"As you would expect, we are offering our French colleagues our full support as they respond."
The director general made the rare public comments as security was stepped up at UK ports and border controls following yesterday's terrorist atrocity in Paris.
More cars and lorries are being searched on cross-Channel routes, and a more visible security operation is in place at the Eurostar terminal in Paris at the Gare du Nord.
The measures have been put in place "on a precautionary basis" but there has been no change to the threat level in the UK, Downing Street said.
A Downing Street spokeswoman said: "The intelligence does not suggest there is any change in the threat level here but on a precautionary basis we have tightened up border security, particularly at our juxtaposed controls.
"For example, at ports people going through them will see increased car and truck searches, a bit more scanning of freight.
"They will also see an increased visible presence, for example at our juxtaposed control at Gare du Nord in Paris.
"This is about looking at what we think is appropriate given the incident, but is not based on any change to the threat level."
An additional police counter-terrorism officer has been sent to Paris to join the British team of experts there, the spokeswoman said.
The Foreign Office is working with UK embassies across Europe to keep Britons updated about the latest advice, No 10 added.
The UK's response to the massacre of 12 people during a raid on the Paris office of satirical magazine Charlie Hebdo was considered at a meeting of the Cobra emergency committee chaired by Home Secretary Theresa May.
The meeting was also attended by the Metropolitan Police and representatives from the intelligence agencies, although the decision to beef up border controls was taken yesterday in the aftermath of the attack.
The No 10 spokeswoman said: "In places like Calais or the Gare du Nord, people can expect to see an increased visible security presence."
The measures would also be "at other ports" and "based on what the authorities and the Border Force think are appropriate".
The Joint Terrorism Analysis Centre (JTAC) raised the terror threat level to severe - the second highest alert - in August, and there has been no change.
The spokeswoman said: "The important thing to note is that JTAC has not changed the threat level, it remains at severe, and when it was changed to severe that already informs our response.
"So we were already operating on a basis of (an attack being) highly likely.
"But, as a British citizen, I want to know that if there is an attack in a neighbouring country that has port crossings into ours, you would expect our authorities to be looking at doing all they can to keep us safe."
Asked if the measures were aimed at preventing those responsible for the Charlie Hebdo attack entering the UK, the spokeswoman said: "Obviously we will be working with the agencies and doing all we can to stop any perpetrators or those linked with the attacks reaching the UK, but it is not ... based on anything specific that suggests that is likely."
She added that she was not aware of anything to suggest that there was anything to link the suspects to the UK.
Home Secretary Theresa May said: "T he cowardly attacks that took place in Paris yesterday have shocked and sickened people in the UK and around the world. And they are a reminder of the very serious threat we face from terrorism.
"In deliberately targeting and murdering journalists, the terrorists were attacking freedom and democracy. And in murdering police officers, they attacked the people who risk their own safety every day to protect us and our way of life.
"Yesterday, the Prime Minister spoke to President Hollande, and British officials are in close contact with their French counterparts. We have offered France every assistance necessary, including the full cooperation of our police and security and intelligence agencies.
"Following the attacks, we took the precautionary step yesterday of increasing security at the French/UK border.
"The UK threat level, which is set by the independent Joint Terrorism Analysis Centre, JTAC, remains at severe. That means that a terrorist attack is 'highly likely' and the public should remain vigilant.
"And this morning I chaired Cobra to consider Britain's response to the attacks and our own preparedness for a similar attack.
"People from all faiths and walks of life have expressed their disgust at the events that took place in Paris.
"I want to reiterate our commitment to standing with the French people against terror. The thoughts and prayers of all of us are with the families, friends and colleagues of the victims."
British Transport Police said they have increased armed patrols at London's St Pancras station to provide reassurance to the public at the Eurostar terminal.
A spokesman said: "Since 2012, we have deployed armed officers within London.
"The safety of rail passengers and staff is of paramount importance to us, and we want to provide a reassuring, visible armed presence to deter terrorism on the rail network.
"In light of the events in Paris, we have increased patrols at St Pancras, in order to maintain and provide enhanced visibility and reassurance to the public. We keep our security arrangements under constant review."