Estonian President Toomas Hendrik Ilves and Prime Minister Taavi Rõivas led the Estonian nation in expressing sorrow over the attacks at a Paris newspaper that killed 12 on Wednesday.
"I was shocked to the core by the act of terror that claimed so many victims at the offices of Charlie weekly in Paris," wrote President Ilves in a letter to French President François Hollande, quoted from in Estonian on Ilves's Facebook page.
"We must maintain resolve and stick to our values - one being our freedom of speech and opinion - just as we stand up against evil, hatred and violence that would deny freedom of speech.
"Estonia mourns with the loved ones and friends of those killed in this act of violence, and our hopes are with the wounded and their families. Estonia is thinking of France in these difficult days."
The attack by men in masks brandishing automatic weapons, thought to be linked to fundamentalist groups angry about portrayals of Islam, left 12 dead and more wounded.