[JURIST] FBI Director Robert Mueller told the US Senate Committee on Intelligence [official website] Wednesday that the FBI remains concerned about attacks by al-Qaida and related terrorist groups, particularly the threat of attack from covert operatives already inside the US, al-Qaida's intention to use chemical, biological, radiological, nuclear or high-energy explosives in an attack, and the potential for al-Qaida' to leverage extremist groups with connections to the terror network and to exploit radical American converts and other indigenous extremists. Mueller also testified that a variety of domestic terrorists, including animal rights and environmental extremists, US-based black separatist groups, the right-wing Patriot movement, and anti-abortion extremists also pose a threat. Read Mueller's prepared testimony [text] in full. Additional testimony [statement list] from Wednesday's hearing on current and projected national terrorist threats to the US is also available. AP has more.