MOSCOW // Confusion over the whereabouts of National Security Agency whistleblower Edward Snowden grew yesterday after a plane took off from Moscow for Cuba with an empty seat booked in his name.
In a live news conference, the founder of the anti-secrecy group WikiLeaks, Julian Assange, refused to reveal Mr Snowden's location but insisted he was safe.
Mr Snowden has applied for asylum in Ecuador, Iceland and possibly other countries, he said.
An Aeroflot representative said Mr Snowden had not boarded flight SU150 to Havana, which was filled with journalists from agencies and newspapers, who were trying to track him down.
Security around the aircraft was heavy before boarding and guards tried to prevent the scrum of photographers and cameramen from taking pictures of the plane, heightening the speculation that he might have been secretly escorted on board.
The Interfax news agency, which has extensive contacts with Russian security agencies, cited a source as saying that Mr Snowden may have flown out in a different plane unseen by journalists.
Others speculated that Russian security agencies might want to keep Mr Snowden in Russia for a more thorough debriefing.
Mr Snowden has not been seen since he arrived in Moscow on Sunday from Hong Kong, where he had been hiding for several weeks to evade US justice and left to dodge efforts to extradite him.
After spending a night in Moscow's Sheremetyevo Airport, he had been expected to fly to Cuba and Venezuela en route to possible asylum in Ecuador.
Interfax quoted an unidentified "well-informed source" in Moscow saying that Russia has received a US request to extradite Mr Snowden and responded by saying it will consider it.
The same source said that Russia could not detain and extradite Mr Snowden since he had not crossed the Russian border.
Justice Department officials in Washington did not immediately respond to an email seeking comment.
Experts said it was likely that the Russians were questioning Mr Snowden, interested in what he knew about US electronic espionage against Moscow.
"If Russian special services hadn't shown interest in Snowden, they would have been utterly unprofessional," Igor Korotchenko, a former colonel in Russia's top military command turned security analyst, said on state Rossiya 24 television.
Aeroflot said earlier that Mr Snowden had registered for the flight using his American passport, which the United States recently annulled.
Ecuador's Foreign Minister Ricardo Patino said his government had received an asylum request, adding yesterday that the decision "has to do with freedom of expression and with the security of citizens around the world." WikiLeaks also said it would help Mr Snowden.
Ecuador has rejected the United States' previous efforts at cooperation, and has been helping Mr Assange avoid prosecution by allowing him to stay at its embassy in London.
But Mr Assange's comments that Mr Snowden had applied in multiple places opened other possibilities of where he might try to go.
WikiLeaks has said it is providing legal help to Snowden at his request and that he was being escorted by diplomats and legal advisers from the group.
Mr Snowden gave documents to The Guardian and The Washington Post newspapers disclosing US surveillance programs that collect vast amounts of phone records and online data in the name of foreign intelligence, often sweeping up information on American citizens.