Moscow (CNN) -- Authorities in Russia detained 14 suspected radical Islamists in a raid in eastern Moscow overnight and seized explosive devices and weapons, the Interior Ministry said Wednesday.
Those detained are suspected of belonging to Takfir wal Hijra, a radical Islamist group that has its roots in Egypt.
Police and officers from the FSB state security service found three homemade explosive devices, along with detonators, guns, grenades, bullets and extremist literature, the media office for the Interior Ministry said.
The group had been funding its activities by "conducting general crime," it said.
No information was available on whether the group may have been planning a terrorist attack, the ministry said.
A 15th person was arrested in a different location later Wednesday, authorities said.
Russia's Supreme Court declared Takfir wal Hijra to be a banned extremist group in September 2010.
In a statement, the Interior Ministry said an investigation is under way and a criminal case is to be opened.
The group was seeking to recruit more people to radical Islam, it said.
"We established that one of the detainees had been studying Islam in Arabic countries for a long time and then came to Moscow," the statement said.
The suspect formed a group with 15 members, including citizens of the countries of Turkmenistan, Uzbekistan and Dagestan, as well as the Russian republics of Chechnya, Ingushetia and Kalmykia, it said. There are also two converts from Moscow and Russia's Belgorod region.
The authorities' search operation revealed the group "is involved in a series of crime, thefts, assaults and other crimes including the spread of forbidden agents, drugs and smoking mixtures," the statement said.
Earlier this month, a Russian man was arrested on suspicion of recruiting young women to join Takfir wal Hijra, state news agency Itar-Tass reported.
A number of the suspects detained Wednesday come from Russia's North Caucasus region, where Islamist insurgents are fighting Russian security services because they want to set up their own independent Islamic state.
Militants from the region have vowed to do all they can to disrupt the Winter Olympics to be held in the Russian resort city of Sochi next February.
CNN's Alla Eshchenko reported from Moscow and Laura Smith-Spark wrote in London. CNN's Phil Black and Zarifmo Aslamshoyeva contributed to this report.