Japan is recruiting ninjas due to a mass shortage in the city of Iga.

Ninjas in Iga

Ninjas in Iga

The area prides itself on being part of the origin of ninja, but in the modern world it appears that numbers are falling.

In an episode of NPR's 'Planet Money', Sally Herships visited the city and said: ''There's a ninja shortage. Or, to be accurate, a ninja-performer shortage.''

Each year, Iga is a hotbed for tourists hitting the area for the annual ninja festival, but the city is struggling with an ageing, depleting population itself, as many of its younger people are lured to the big cities rather than staying in rural Japan.

This means there aren't enough ninjas in the area, which could damage Iga because of its heavy reliance on tourism brought by the festival.

Mayor Sakae Okamoto added: ''We hold this ninja festival between late April to around the beginning of May. During this period visitors and also local people come here.

''Everybody will be dressed like a ninja and walks around and enjoys themselves -- but recently I feel that it's not enough.''

The salary for a ninja - who must be highly skilled - can range from £18,000 to £65,000, according to the mayor.