The UK has tightened border security at all ports and train facilities due to the attack on the offices of French magazine, Charlie Hebdo.
Armed police patrols can be seen in central London and Westminster where government offices and House of Parliament are located.
Media reports say security in the capital has intensified overnight.
However, the government confirmed there is no immediate terror threat to the UK, ruling out raising the national terror threat.
The Prime Minister's spokesman announced that while there had been no change to the threat level, the government decided to take extra security measures.
In August, the Independent Joint Terrorism Analysis Centre (IJTAC) raised the UK's terror threat level from "substantial" to "severe,” which denotes that a terror attack is highly likely.
The spokesman said in a press conference that train stations in France allowing people to travel to the UK had also been tightened.
Meanwhile, Home Secretary Theresa May is chairing the Cabinet Office Briefing Rooms (COBR) meeting to discuss the implications of Paris terror attack on the UK.
Before the meeting, May said that the authorities have intensified checks on passengers, goods and vehicles coming the UK from France and other parts from Europe.
She added that these measures will remain in place for the time being.
The UK Foreign and Commonwealth Office has advised British nationals in France to take extra care and follow the security advice issued by French authorities.
About 17 million British nationals visit France every year.
“There is a high threat from terrorism. Attacks could be indiscriminate,” FCO said in its update travel advice on France.
Due to ongoing threats to France by Islamist groups, and recent French military intervention against the Islamic State, the French government has warned the public to be especially vigilant and has reinforced its own domestic and overseas security measures, it added.