France's Interior Ministry is reinforcing security measures on public transport in the Paris region after a deadly bomb blast hit a Russian subway train.
French Interior Minister Mathias Fekl said in a statement Monday the decision was a "measure of precaution" after the explosion in St. Petersburg.
The statement provided no further information about the reinforced security, and Fekl's office did not immediately respond to requests for comment.
Armed soldiers patrol subways, airports, museums and other sites around France as part of heightened security measures imposed after deadly Islamic extremist attacks in 2015.
The French Embassy in Russia urged French citizens anywhere in the country to exercise "the most extreme vigilance" and avoid public transport.