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.

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.

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.”

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.