A number of attacks have taken place in Paris, the capital city of France.
Sadly over 120 people were killed.
Police and soldiers were called in to help keep people safe.
Lots of people all over the world have shown their support by taking part in candlelit vigils.
Some of you might have questions or might be feeling a little bit worried about what has happened in Paris - So we are asking our security expert Frank Gardner to try to answer as many of your questions as possible.
This chat page is now closed. Thank you for sending in your questions.