Investigators said two blasts occurred outside of the headquarters in Makhachkala about 15 minutes apart, Interfax reported.
"Two cars were detonated within several minutes. At least eight people have been killed," a representative of Dagestan's Investigative Committee said. "More than 20 cars have been damaged."
TV Novosti said unconfirmed reports indicated at least 22 people were injured.
Jessica Simpson shares three-way kiss with friends in photo
Senate Democrats to pull all-nighter on climate change