MOSCOW — A Moscow court has arrested a 14-year-old boy believed to be linked to a bomb attack at a local branch of Russia's main intelligence agency in a northern city last week.

The court on Tuesday ruled to keep behind bars the teenage Moscow resident, whose name is not disclosed because he is underage. Russian news agencies reported that investigators believe that the teenager has ties to a 17-year-old male technical college student who set off the bomb Wednesday at a branch of the FSB in the city of Arkhangelsk. The attack injured three security officials and killed the student.

Authorities called it a "lone wolf" attack but said the bombing prompted an investigation into an anarchist chat group where he had posted a warning.