MOSCOW, June 6 (RAPSI) - The Federal Security Service (FSB) has detained Yulai Davletbayev, who allegedly masterminded a terrorist attack which was foiled in Moscow last month, Russia's National Anti-Terrorism Committee reported on Thursday.

The alleged terrorist was detained near Moscow, however the operation is not over yet, a source at the Russian security services has told RIA Novosti.

A terrorist attack was allegedly planned for May 9 Victory Day in Moscow by the Islamic Party of Turkestan, an al-Qaeda affiliated terror group.

Two terrorists said to be involved in organizing the attack were killed and one was detained in Orekhovo-Zuyevo near Moscow. According to the media, the flat where they lived was rented by Davletbayev from Sterlitamak, Bashkortostan.

The National Anti-Terrorism Committee said that the group escaped the law-enforcement agencies after committing a number of crimes in Russian republics in the Volga region. In 2010 they underwent military and ideological training at an international terrorist organization in an area on the border of Afghanistan and Pakistan.

The Islamic Party of Turkestan, also called the Islamic Movement of Uzbekistan or IMU, has been declared a terrorist organization by the Russian Supreme Court. Its operation is prohibited in many countries in Europe and Central Asia, as well as in the United States. FSB Director Alexander Bortnikov believes that it is no less dangerous than al-Qaeda.

In March 2013, the Russian Interior Ministry announced the detainment of the leader of the IMU's Moscow branch. He was to be extradited to Uzbekistan.