One of Greece's most-wanted fugitives was captured Saturday nearly a year after the convicted Marxist extremist failed to return to prison while on a furlough, police said.

Christodoulos Xiros, 56, was arrested in the suburb of Anavyssos, southeast of Athens, police chief Dimitrios Tsaknakis told reporters.

"When he was arrested, he was riding a bicycle and had changed his appearance by growing his hair long, growing a beard and wearing glasses," Tsaknakis said.

Xiros was carrying a loaded pistol, but didn't resist arrest, he said. The pistol's serial number and make were scratched out.

Xiros had also dyed his hair blond to change his appearance. Tsaknakis added that police had been following Xiros for months and had been staking out the house he lived in. The operation unfolded slowly, because the house Christodoulos lived in was in an open space and offered several escape routes, Tsaknakis explained.

Police officials, speaking on condition of anonymity because they weren't authorized to talk about the case, said a search of the house had turned up seven AK-47 assault rifles, a rocket-propelled grenade launcher and a keg with an unidentified explosive.

Xiros was serving six life terms, plus 25 years, for his role in Marxist group November 17, which killed 23 people, including Greek politicians, businessmen and British, American and Turkish diplomats and military officials, from 1975 to 2000.

Xiros and most of the November 17 members were arrested in the summer of 2002, after a botched attempt at planting a bomb resulted in a premature explosion at the hands of Xiros' younger brother, Savvas. They were convicted in December 2003 and again, on appeal, in May 2007.

Xiros had vanished while on furlough on Jan. 7, 2014. Weeks later, he had released a video criticizing the handling of Greece's financial crisis, threatening politicians and journalists and vowing further attacks.

Xiros' absconding, on his seventh furlough in 13 months, led to authorities abolishing furloughs for convicted terrorists and long-serving criminals.

It also led Greece to accelerate the transformation of a prison in a remote area in central Greece into a maximum-security facility. The facility, Domokos Prison, now has 17 inmates, most of them convicted terrorists, all of whom were transferred this past week. Alexandros Yiotopoulos, the purported leader of November 17, Dimitris Koufodinas, the organization's chief executioner, and another member were transferred to Domokos on Friday.