Clad in samurai armour, Ishin Takahashi was among thousands who took part in an ancient festival at the weekend in the shadow of Japan's crippled Fukushima nuclear plant.

With an evacuation order following last year's atomic crisis and rampant fears about radiation, the 1,000-year-old "Soma Nomaoi", or wild horse chase, was all but cancelled following the March 11, 2011 quake-tsunami disaster.

But a year later, Takahashi and others wearing 10th Century period costumes hope that reviving the traditional festival will help lift spirits in their disaster-struck community -- and inspire the younger generation.

"This is a symbolic first step to recovery," the 69-year-old told AFP as a scorching sun beat down on Minamisoma, a small community about 20 kilometres (12 miles) from the nuclear plant that went into meltdown after it was swamped by the giant tsunami.

"Some of our communities remain devastated, but I'm sure we can rebuild them or make them even better."

Minamisoma remains largely a shell of its past with many residents having fled to other communities across Japan over fears about living in the shadow of the doomed reactors -- the site of the worst nuclear accident in a generation.

But on Saturday its street came alive with locals -- many of them returning just for the festival -- galloping triumphantly on horses around a specially-built hippodrome for the three-day festival.

Clad in decorated helmets and carrying razor-sharp traditional Japanese swords, participants swaggered about on horseback followed by a feudal lord's procession decorated with colourful banners displaying their family crests.

The sound of conch horns echoed through the streets with tens of thousands of visitors coming out to see the ancient show of military pomp and pageantry featuring about 400 hundred horses.

"Nomaoi is my motivation in life," said Kohei Inamoto, a 20-year-old plant worker who temporarily returned for the event after he and his family fled to Chiba, south of Tokyo.

"Nomaoi is my 'soul' connection with my hometown. If there were no Nomaoi, I would have abandoned my hometown."

Inamoto was among many who missed last year's scaled-back festival which saw most of the top events, including horse racing and capturing flags shot into the air by fireworks, cancelled.

The heritage event aims to recreate a medieval battlefield, having originated from secret military exercises held by samurai warriors from the tight-knit Soma clan.

"I'm glad to see the festival come back... but we are too old to keep it going," said Shigeru Ouchi, 60, standing beside his steed.

"I'm concerned that young people are disappearing from the town after the disaster, but I hope the remaining youth will take it over and pass the baton to the next generation," he added.

For decades small Japanese communities have seen younger people leave for larger urban centres, but the crisis has stoked that exodus and worried older residents fear that the festival might never reclaim its former glory.

"We still can't hold Nomaoi in style, as it used to be, until the nuclear accident is settled, but I will die before I see that," Kosaku Motobayashi, 77, said quietly.

Hideki Noda, a 23-year-old farmer, said he wants to keep the festival alive but didn't know when he could return to his hometown just a few kilometres from the stricken reactors.

"I'm proud of the festival," said a smiling Noda. "The younger generation should take the lead in maintaining the 1,000-year-old tradition, no matter what."

The quake-sparked tsunami left some 19,000 dead or missing and knocked out cooling systems at the Fukushima plant, causing meltdowns that spread radiation over a large area and forced thousands to evacuate.

Some have moved back to nearby communities, but many more have not and there are fears it could be decades before nearby towns are deemed safe to live in.

"I can't come back now but I will return as a descendant of Soma samurai, at any cost," said 59-year-old evacuee Yoshiyuki Itakura. "My will is unshakable."

Even holding this year's festival was a challenge, with organisers spending a year preparing. They decontaminated the racing course and spectator stands and brought in horses from other regions.

About 100 local horses used in past festivals drowned in the tsunami or died of starvation after the area surrounding the plant was designated a no-go zone.

"I would like to send a message to the world that victims of the disaster are holding this event with a renewed sense of spirit," organiser Koichi Fujita said.

"We hope this will help speed up reconstruction of our community."