TOKYO -- Japan on Thursday hanged a 73-year-old man convicted of murder and robbery, the country's sixth execution of the year.

The Justice Ministry said the hanging was carried out in Tokyo. The man had shot to death a restaurant owner in 2004, stealing his bag containing 400,000 yen ($4,000) in cash.

Japan executed three inmates in February and two in April. There are 132 inmates currently on death row.

All executions in the country are done by hanging.

Human rights groups have widely criticized Japan for continuing capital punishment, but polls show the public supports the system.

Japan's government releases few details about executions, and inmates are not informed of their pending execution until immediately before it is carried out.