Lithuanian news portal Delfi on Thursday received a letter containing a threat to launch a Charlie Hebdo-style attack on its journalists, prompting the evacuation of its employees.

The letter, directed to the outlet’s editor in chief Monika Garbačiauskaitė-Budrienė, was written in Russian and enclosed with a bag of brown powder.

“Bitch—Garbačiauskaitė-Budrienė....