By VLADIMIR

ISACHENKOV

Associated Press

MOSCOW — A man was arrested Saturday in connection with a St. Petersburg supermarket bombing that wounded 18 people, Russia’s main domestic security agency said.

Eight people remain hospitalized after a device exploded Wednesday in a storage area for customers’ bags. Investigators said the homemade device contained 200 grams of explosives and was rigged with shrapnel to cause more damage.

The Federal Security Service, or FSB, did not identify the suspect or provide any details about his motive. The agency said in a statement carried by Russian news agencies that he organized and carried out the attack on his own.