French daily Le Parisien reported that letters were sent to IKEA in France and in Germany saying the firm's French stores would be bombed unless it paid several million euros to the blackmailer, raised workers' salaries and made donations to charities.
An IKEA spokeswoman in Stockholm confirmed the company had received threatening letters about its French operation and said security had been beefed up. She declined to give information about the nature of the threats or about the security measures.
IKEA France said the threatening letters demanded that the company increase donations to charities. It did not elaborate.
French police were not immediately available to comment.