(Adds U.S. comment, paragraphs 6-7)
By Renee Maltezou
ATHENS, Jan 22 (Reuters) - Greece on Wednesday offered a record 4 million euro ($5.4 million) bounty for help in capturing five fugitives after one of them went on the run during a prison furlough, deeply embarrassing authorities.
Christodoulos Xiros, 56, was serving multiple life terms in Athens for his role in Greece's most lethal guerrilla group when he was let out for a week over the New Year and never reported back to prison.
Xiros, whose Marxist November 17 group claimed responsibility for attacks that killed Greek, U.S. and British businessmen and diplomats, has since appeared on video vowing to avenge the pain that ordinary Greeks have suffered under two international bailouts.
He has called on leftists and anarchists to unite against police, journalists and politicians whom many Greeks blame for their country's debt crisis and the job losses and widespread poverty that followed.
November 17 was dismantled in 2002 after a bomb exploded in the hands of Xiros' brother Savas. More than 10 members of the group were convicted for 23 killings and dozens of bomb attacks spanning three decades.
In Washington, State Department spokeswoman Marie Harf said the United States is "very closely engaged" with Greek authorities about finding Xiros.
"We're obviously deeply concerned that this convicted terrorist remains at large and is now allegedly issuing renewed calls for violence. ... We continue to call on the (Greek) government to do everything they can to locate him and return him to prison."
Many Greeks are asking why a convicted guerrilla group member was allowed to leave prison without being monitored.
"The Greek state, the state mechanism will do everything within its constitutional obligations to protect the country, the people," Civil Protection Minister Nikos Dendias told reporters.
He set a reward of 1 million euros ($1.35 million) for information leading to the capture of Xiros and the same amount each for two members of another guerrilla group, the anarchist Revolutionary Struggle.
Police said 1 million euros would also be offered for two gunmen who shot and killed two young supporters of the ultra-right Golden Dawn party, outside the party's offices in Athens in November. An anti-establishment group has claimed the drive-by shooting. ($1 = 0.7383 euros) (Additional reporting by Will Dunham in Washington; Editing by Ruth Pitchford and Cynthia Osterman)