LONDON (AFP) - US intelligence leaker Edward Snowden has applied to another six countries for asylum, WikiLeaks said on Friday on its Twitter feed.

The 30-year-old is believed to be holed up at a Moscow airport looking for a country that will give him safe haven. Snowden has previously asked 21 countries for asylum.

"Edward Snowden has applied to another six countries for asylum," said the tweet from anti-secrecy website WikiLeaks, which is helping Snowden and has one of its staffers with him in Moscow.

"They will not be named at this time due to attempted US interference." Washington has revoked the passport of Snowden, who is seeking to evade US justice for leaking details about a vast US electronic surveillance programme to collect phone and Internet data.