AMMAN, Jordan  —  A Jordanian judicial official says a 30-year-old man has been arrested for allegedly killing his sister to cleanse the family's honor.

The official says the man, who lives in the southern city of Aqaba, used his traditional robe to strangle the woman.

The official spoke Tuesday on condition of anonymity because he's not authorized to speak to the media.

The man confessed to Sunday's killing, saying his sister would leave the family home without their approval.

In conservative Jordanian society, unsupervised movements by women damages a family's honor.

An average of 20 Jordanian women are murdered annually in honor killings. The government has tried to solve the problem with harsher sentences to perpetrators.