Top US intelligence official: Syrian al-Qaida-linked militants training to attack US, Europe

The top U.S. intelligence official says a Syrian militant group tied to al-Qaida, the al-Nusra Front, aspires to attack the United States.

Director of National Intelligence James Clapper told the Senate Intelligence Committee Wednesday that such al-Qaida groups have started training camps "to train people to go back to their countries," and conduct more terrorist acts.

Clapper says some 26,000 rebel fighters battling the government of Bashar Assad in Syria are extremists with about 7,000 of them foreigners from some 50 countries, including Europe.

U.S. intelligence officials have said a handful of American foreign fighters, and hundreds of European militants have already returned to their home countries. The officials spoke on condition of anonymity because they were not authorized to speak publicly.