Moscow, June 11 : Russia's Federal Security Service (FSB) said that it foiled a terrorist attack in Simferopol, the capital of Crimea, and detained five suspects. It was established that the detainees were preparing to plant a makeshift explosive device in a market and had also propagated terrorism and extremism online, Xinhua news agency quoted an FSB statement as saying on Wednesday. All the five detainees were Russian, according to the FSB. Homemade explosive devices, ammunition, small arms, knives and communications equipment containing information about planned crimes, as well as contacts with representatives of radical Ukrainian forces fighting in southeast Ukraine were seized, the statement said. Currently, initiating a criminal case against the detainees on the grounds of preparing a terrorist attack is being considered, which may mean a prison term of up to 20 years for the suspects, according to the FSB. Russia had annexed Crimea in 2014, although it is also claimed by Ukraine. /IANS