Prime Minister David Cameron today warned that "a number of British casualties" were expected in the horrific Paris attacks that claimed over 120 lives and stated that the UK's terror threat level remained at "severe".
"However much we prepare, we in the UK face the same threat. The UK's terror threat level remained at "severe", but the attack would prompt a review," Cameron said, adding that he was "shocked" by the gun and bomb attacks.
"Our thoughts and prayers are with the French people. We will do whatever we can to help.
"Your pain is our pain, your fight is our fight. The attack showed the threat posed by Islamic State militants was evolving," Cameron added.
The Foreign Office said it is "urgently investigating" whether any British nationals have been caught up in the shootings or hostage-taking.
There will be "strengthened policing at ports" and more police at public events in the coming days, UK police said.
Met Police Assistant Commissioner Mark Rowley and national policing lead for counter terrorism called for "vigilance" from the public.
Meanwhile, Queen Elizabeth II has sent her condolences to French President Francois Hollande.
"Prince Philip and I have been deeply shocked and saddened by the terrible loss of life in Paris. We send our most sincere condolences to you, the families of those who have died and the French people," she said.
Downing Street said Cameron would chair a meeting of the government's Cobra emergency committee in the wake of the attacks.
France was rocked by multiple, near simultaneous attacks on entertainment sites around Paris last evening that claimed over 120 lives.
At least two explosions were heard near the Stade de France national stadium where a France-Germany friendly soccer match was being played with President Francois Hollande in attendance.
