DAVOS, Jan 24: Iran must extradite jailed Al Qaeda captives and crack down on others still at large who may be fomenting attacks on the United States, a senior US official said on Saturday.

The official renewed White House demands that Tehran, which said on Friday it would put on trial a dozen Al Qaeda captives, should instead hand them over to their countries of origin so that they could be interrogated about plans for future attacks.

He said Washington feared Al Qaeda members were still operating in Iran.

"The Iranians need to think very carefully before they allow a group of senior Al Qaeda members to operate on their territory while they foment attacks against the US or our allies," the official said.

"It would not be in their long-term interests, in terms of trying to improve their relations with the US." The official was speaking to reporters at the World Economic Forum in Davos, Switzerland.-Reuters