From Moscow to LA, security measures tightened following Paris attacks

A white rose is attached to a barrier as a French policeman with an automatic weapon secures the area near the Bataclan concert hall the day after a series of deadly attacks in Paris, France, November 14, 2015 © Benoit Tessier
Security is being stepped up across the globe, with national governments holding emergency meetings to review security threats. Officials are asking the public to remain vigilant and not to panic following the devastating terror attacks in the French capital.

LIVE UPDATES Paris attacks: 120+ killed and many injured in a series of terrorist acts

While France has declared state of emergency and closed its borders following a series of attacks in Paris, reportedly carried out by terrorists inspired by Islamic State (IS, formerly ISIS/ISIL), security measures have been reinforced by a number of other states. These include France’s neighbors in Europe, as well as countries such as Russia and the US.

Russia's Anti-Terrorist Committee said the necessary measures are being taken "in light of the new threats." "The entire national security network has been put on high alert," the Committee said in a statement.

Russia's Transportation Ministry "will take measures related to transportation security," the ministry's head Maksim Sokolov told journalists on Saturday. Security has been bolstered at all Moscow airports, a source familiar with the situation told Interfax; Russian Railways also announced additional steps to strengthen its security.

READ MORE: Terminal at London Gatwick Airport evacuated as ‘precautionary measure’

The UK is on a higher security alert, with security bolstered and additional checks introduced at international transport hubs. A number of key locations in British cities have also seen their security heightened, while the government is reviewing the current national threat level.

Officials fear the terror attacks are "not over yet," the Telegraph reported, citing a British counter terrorism source. London was already on heightened alert for possible terrorist revenge attacks, after a notorious IS executioner known as Jihadi John was killed in a drone attack in Syria this week.

The Netherlands will tighten security at its borders, airports and railway stations, with all traffic to and from France to be closely monitored. Reuters cited Dutch Prime Minister Mark Rutte telling journalists on Saturday that the country is "at war" with IS.

"ISIS is our enemy. We are at war with ISIS. We are not at war with a country, a belief or with Islam," Rutte said, adding, "Our values and our rule of law are stronger than their fanaticism."

Security had also been reinforced in Italy, the Italian Prime Minister Matteo Renzi said. The risk of similar episodes should not be underestimated, Reuters cited Renzi as saying in a television address, with the minister adding that his country is standing by France, and that the attacks in Paris run counter to "all of humanity" and "our way of life."

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German authorities are analyzing the country's threat level, DW reported. German security officials were in close contact with their French counterparts, as Germany "remains in the focus of international terrorism," an Interior Ministry spokesperson said on Saturday.

Security is stepped up in the Austrian capital, Vienna, which is hosting an international meeting concerning the conflict in Syria. A French school was closed and city officials cancelled a popular Christmas market.

In Belgium, the authorities announced they had increased checks on their borders, especially with France, starting from early Saturday. In Switzerland, the Swiss Security Service and the Border Guard are on "high alert," and the Federal Police have strengthened security measures around buildings of French diplomatic missions. In Spain, a national security council meeting chaired by Spanish Prime Minister Mariano Rajoy has been planned for Saturday.  

READ MORE: ISIS claims responsibility for Paris attacks, threatens more violence 

With the Paris attacks raising security concerns for all countries involved in fighting IS, major US cities have also been stepping up security. The New York Police Department dispatched its "critical response group" equipped with high-powered weapons and other security to crowded areas of the city, NBC reported.

Police in Los Angeles were stepping up patrols at half dozen events, including popular artists' concerts. San Francisco police were also on "high alert," the channel reported citing officials. Boston's Regional Intelligence Center was "on it from the beginning," a senior law enforcement source said.

IS claimed its militants were behind the shootings and bomb attacks in the French capital on Friday, in which hundreds of people were killed or injured. IS terrorists conducted a "blessed attack on... Crusader France," the group claimed in an internet post on Saturday. It also threatened further attacks, as long as the military campaign against the jihadists continues. In another statement, the terror group has claimed responsibility for bombing a Russian passenger jet over Egypt, which killed 224 people on board.

READ MORE: Sinai crash: St.Petersburg’s bells toll for each of 224 victims as new intel says bomb to blame 

"What ISIS is trying to establish is that they can operate anywhere and that everybody is potentially vulnerable. Their ability to reach out and do this all the way down to the common man and woman on the street is something that creates the havoc," a former CIA officer Jack Rice told RT.

But it's not only toughened security that has become a common move for a number of nations. Following the Paris tragedy, people from all over the world have been united in solidarity with all those affected by the horrific attacks.

Landmark buildings across the world were illuminated in the colors of the French flag, while thousands of people have been sending their prayers on social media, with the iconic Eiffel Tower becoming a universal peace symbol of support, understanding and love.