Officials with Russia's domestic intelligence service, the FSB,have yet to comment on whether the derailment was caused by terrorism.

VOA: standard.2009.11.27

Senior Pakistani military officials would not comment on the passports, and they have not been independently verified as genuine.

VOA: standard.2009.10.30

The U.S.Federal Bureau of Investigation and other federal law enforcement agencies are providing assistance to Mexican authorities in this investigation, but they have declined to comment on the developments in Mexico.

VOA: standard.2010.04.01