WikiLeaks says the U.S. government is trying to force the Internet whistle-blower site to hand over details of its Twitter accounts.

In a statement Saturday, WikiLeaks said officials have subpoenaed details of its account from the San Francisco-based Twitter Inc., seeking private messages, contact information and other personal details of founder Julian Assange and three other people associated with the website.

WikiLeaks said that it suspected other U.S. Internet providers have been contacted by federal government officials as part of their investigation into possible charges against the website and its staff.

WikiLeaks vowed to fight the court order to release the Twitter account information, saying it amounted to harassment.

"If the Iranian government was to attempt to coercively obtain this information from journalists and activists of foreign nations, human rights groups around the world would speak out," Assange said in the statement.

Washington has been considering possible charges against WikiLeaks and its staff following a series of spectacular leaks of frank and often embarrassing U.S. diplomatic cables.

A copy of the court order, posted to, said the information sought was "relevant to an ongoing criminal investigation" and ordered Twitter not to disclose its existence to Assange or any of the others targeted.

The order was unsealed "thanks to legal action by Twitter," WikiLeaks said.

Twitter has declined comment on the claim, saying only that its policy is to notify its users, where possible, of government requests for information.

WikiLeaks said it suspects that other Internet firms, such as Facebook Inc. and Google Inc., have been served with similar court orders and urged them to "unseal any subpoenas they have received."

Google and Facebook have not commented on the WikiLeaks statement.

The Twitter subpoena names Assange, Bradley Manning, the U.S. Army private suspected of being the source of some of WikiLeaks' material, as well as Birgitta Jonsdottir, an Icelandic lawmaker and one-time WikiLeaks collaborator.

The U.S. is also seeking details about Dutch hacker Rop Gonggrijp and U.S. programmer Jacob Appelbaum, both of whom have previously worked with WikiLeaks.

Gonggrijp praised Twitter for informing him of the subpoena. "It appears that Twitter, as a matter of policy, does the right thing in wanting to inform their users when one of these comes in," Gonggrijp said. "Heaven knows how many places have received similar subpoenas and just quietly submitted all they had on me."

U.S. officials have been furious with WikiLeaks over the release of tens of thousands of classified documents on the wars in Iraq and Afghanistan and of thousands of classified U.S. diplomatic cables.

U.S. officials say posting the military documents put informers' lives at risk, and posting diplomatic cables made other countries reluctant to deal with American officials.

The U.S. State Department said Friday that it has warned hundreds of people worldwide that they may have been put in danger by the WikiLeaks' releases.

State Department spokeperson P.J. Crowley said those at risk could include civil society activists, journalists or government officials whose discussions with U.S. officials as recounted by WikiLeaks could anger foreign governments or other groups.

"We've identified several hundred people worldwide that we feel are at potential risk," Crowley said. "In a small number of cases, we have assisted people moving from where they are to safer locations."

He did not name any of the people involved.

WikiLeaks denies U.S. charges that its postings could put lives at risk, saying that Washington merely is acting out of embarrassment over the revelations contained in the cables.

But WikiLeaks and its small staff rely heavily on American-based Internet and finance companies to raise funds and get their message out.

Until recently, the group raised donations via PayPal Inc., MasterCard Inc., and Visa Inc., and hosted material on's servers.

But the group's use of American companies has come under increasing pressure as it continues to reveal U.S. secrets.

With files from The Associated Press