U.S. contacts Greece after militant behind Americans' deaths escapes
Christodoulos Xiros waits in the courtroom at the start of the appeals trial of November 17 members at a special court in a top-security Athens jail, Dec. 2, 2005 [AFP]

The United States on Wednesday voiced concern that a far-left Greek militant whose group was behind the killings of five Americans has disappeared while on prison leave.

Washington has been in contact with Athens since Christodoulos Xiros, 56, serving six life sentences for his role as a hitman with the November 17 terror group, failed to return from a nine-day New Year's break.

"We call on the Greek government to locate Xiros and return him to prison," State Department spokeswoman Jen Psaki told reporters.

"The United States and Greece are partners in combating terrorism in all its forms, and we work closely with Greek authorities in confronting those who use violence to seek to achieve their goals."

November 17, which was broken up in 2002, remains on the State Department's list of designated foreign terrorist organizations.

The group's "initial attacks were assassinations of senior US officials and Greek public figures," the State Department says on its website, adding it had begun carrying out bombings in the 1980s.

Psaki said that November 17 had murdered five Americans over the years that it was in operation. Many of them were military, intelligence or defense attaches.

The group was named after a student uprising against Greece's US-backed military junta in 1973.

It carried out a series of assassinations of prominent Greek and foreign targets between 1975 and 2000.

[Image via Agence France-Presse]