TOKYO - Tanks rumbled through the posh Ginza shopping district on Sunday. Soldiers scaled the walls of department stores. Military choppers hovered over skyscrapers like a family of huge dragonflies. It was Tokyo's largest earthquake preparation drill yet.
This year's Big Rescue, an annual event commemorating the huge 1923 quake in the capital that killed 150,000 people, comes amid concern that thousands of temblors on nearby volcanic islands could be a harbinger of the dreaded ''Big One.''
But the large military presence in this year's exercise has been criticized, with many people wary of signs of resurgent militarism.
A union of groups opposed to the drill called it a thinly veiled pretext for a military exercise.
Five protesters wearing helmets tried to jump on the track at one subway station in an attempt to keep soldiers from participating in the drill, and were arrested after clashing with police, a Tokyo Metropolitan Police official said on condition of anonymity.
There were demonstrations at six sites in Tokyo, but the official declined to say how many people participated. Unions and citizens' groups had notified police that about 2,500 people would attend, he said.
Tokyo's hawkish Gov. Shintaro Ishihara alarmed Asians who remember Japan's brutal brand of imperialism when he urged troops in April to watch for rioting foreigners if an earthquake were to strike.
A major quake in the sprawling capital of 11 million people would be devastating. City officials predict a 7.2-magnitude earthquake would kill more than 7,000 people, injure 160,000 and leave at least 2.3 million homeless.
More than a half million buildings would burn or collapse, inflicting hundreds of billions of dollars in damage. World financial markets could be rocked if trading in Tokyo crashed to a halt.
About 7,100 members of ground, maritime and air Self-Defense Forces participated in Sunday's all-day exercise, compared with only about 500 in previous drills. Mock rescue operations ran at 10 locations around the city.
In Ginza, hundreds of soldiers in camouflage cruised the streets in armored vehicles on their way to join firefighters and other rescue personnel assisting the injured, transporting medicine and clearing roadways. Police in riot gear stood by for crowd control.
Onlookers said a bigger role for the Self-Defense Forces in disaster relief was inevitable.
''I understand why people would be opposed, but if a disaster really struck, I don't think the city could handle it by itself,'' said Rika Koike, a 39-year-old housewife.