Give facts, not rumors. If you don't know the answers, be truthful. Here is what we do know. This is not a time to play all-knowing parent. Assure your child he is safe.
Children tend to personalize events that happen on the world stage.
Explain how you've always been there to care for your child and how he has always been safe. Confirm that you will help him stay safe in the future. Much of a child's sense of safety and security comes from daily rituals. Kids need to eat lunch at the normal time. They need their usual afternoon nap.