Saudi security forces discovered Tuesday a large amount of explosives and chemicals at a villa in east Riyadh apparently used by militant groups to store weapons. Police confiscated locally assembled bombs, weapons, chemical and several personal computers and extremist books and leaflets. It was unclear if the villa was inhabited with some neighbors claiming the building was deserted, while others told the security forces that a bearded man was living there. The mystery person would leave the villa at dawn and return at sunrise, according to witnesses.The Ministry of Interior has yet to provide further details about the discovery in Shaker ibn Abi Bakr Street, in eastern Riyadh. The Saudi authorities have confiscated large quantities of weapons and explosives earlier this year and arrested 17 men, suspected of belonging to militant groups.