Tokyo, Sep 17 (Xinhua) Prisons and detention houses in Japan have exceeded their in-take capacities, a news report said.

According to the justice ministry, there were 70,737 detainees in prisons and detention houses till July, the highest in more than 50 years.

However, existing facilities can hold only 60,794 and are operating at 116.4 percent capacity, the Yomiuri Shimbun newspaper reported Sunday.

The total capacity rate in prisons and detention houses surpassed 100 percent in 2001 and has been on the rise.

The number of inmates almost doubled compared with 37,164 in 1993, with an annual increase of 3,000 to 4,000 in recent years, the report said.

The rise in the number of new convicts mainly results from an increase of crimes and the recent trend for judges to hand down longer prison terms, the report said, adding the average prison term increased from 24.4 months in 1996 to 29.5 months.

The justice ministry has been trying to build new prisons and expand existing facilities though the pace cannot keep up with the sharp increase in the number of detainees, the report said.