Two prisoners escaped from a maximum security prison in Athens with a hijacked helicopter on Sunday, authorities said.
Police said the two men one Greek and one Albanian escaped at 6:20 pm (1520GMT) in a private helicopter that had landed in a yard in Korydallos prison, Greece's largest jail.
The helicopter pilot was arrested shortly after landing at a cemetery, a short distance from the prison.
Police said he claimed two men armed with a hand grenade and a pistol had threatened him at the seaside resort of Ayios Kosmas, south of Athens, and forced him to make the flight to the prison. The pilot said the two men threw smoke flares as the helicopter landed in the prison yard, causing confusion, police said.
The escaped prisoners were identified by police as Vassilis Palaiokostas, 40, serving a 25-year sentence since 1999 for the kidnapping of a Greek businessman, and Albanian Alket Rizai, 32, serving a life sentence since 2003 for manslaughter.
Police said one of the men who had helped them escape was Vassilis Palaiokostas' 46-year-old brother, Nikos, one of Greece's most wanted men who escaped prison himself in 1990. Nikos Palaiokostas had been imprisoned for his role in a series of bank robberies, and also was charged in absentia of the same kidnapping as his brother.
Police did not identify the fourth man suspected in the escape.
A manhunt has been launched for all four, who police said had driven off on two motorcycles after the helicopter landed at the cemetery.