Russia's state security service says it has detained seven people in the country's Ural mountain region on suspicion of terrorist activities.

The country's Federal Security Service announced on Monday that the suspects, detained in the regional capital Yekaterinburg, were believed to be plotting to carry out terrorist attacks in Moscow, St. Petersburg and the Ural region.

Law enforcement officials said they uncovered a laboratory for manufacturing explosives and that members of the group were planning to journey to Syria to fight with the Islamic State group.

According to the press release published on the security service's website, the suspects included Russian citizens and citizens of Central Asia states.

Russian authorities estimate that around 3,000 Russian citizens have joined the Islamic State group in Syria.