TOKYO » Canned goods, batteries, bread and bottled water have vanished from store shelves and long lines of cars circle gas stations, as Japan grapples with a new risk set off by last week’s earthquake, tsunami and ensuing nuclear crisis: panic-buying.

Far outside the disaster zone, stores are running out of necessities, raising government fears that hoarding may hurt the delivery of emergency food aid to those who really need it.

"The situation is hysterical," said Tomonao Matsuo, spokesman for instant noodle maker Nissin Foods, which donated a million items including its "Cup Noodles" for disaster relief. "People feel safer just by buying Cup Noodles."

The company is trying to boost production, despite earthquake damage that closed down its facilities in Ibaraki prefecture until Tuesday.

The frenzied buying is compounding supply problems from damaged and congested roads, stalled factories, reduced train service and other disruptions caused by Friday’s magnitude 9.0 earthquake off Japan’s northeast coast and the major tsunami it generated.

Renho, the minister in charge of consumer affairs, who goes by one name, asked people to refrain from buying items they don’t really need.

Michiaki Tada, a 40-year-old Tokyo web programmer, was stunned to find the shelves bare at several convenience stores. He gave up and has just been eating out.

"It’s like a joke. Cup noodles, rice balls, snacks — just about everything, except for super-hot chips, is gone," he said. "I can’t even find chocolate bars."

Family Mart convenience store owner Kazuhiro Minami was expecting a small delivery later Tuesday, but said he would have to shut anyway if the electric utility decides to go ahead with proposed three-hour rolling blackouts.

"I’m really, really worried," he said, blaming hoarding, distribution problems and worries that there might be another quake.

Even in the western city of Hiroshima, which was untouched by the earthquake and tsunami, stores are running out of batteries and the media is warning people not to hoard, a local government official said.

Panasonic Corp., which donated 500,000 batteries, 10,000 flashlights and 300 million yen ($3 million) for quake victims, boosted battery production at its Osaka plant by adding work shifts. It also increased shipments from its battery factories in Thailand and Indonesia.

Retailers said they haven’t seen such panic in years, perhaps since the oil crisis in the 1970s.

"We have been working round the clock to improve supplies to the store," said Anthony Rose, a Hong Kong-based vice president for Wal-Mart Asia, which owns the Japanese supermarket chain Seiyu Ltd. "There should be a positive shift in the next 48 hours."

"The needs are surging because people are suddenly preparing for emergencies and stocking up on bottled water, cup noodles and other items with a long shelf-life," said Shoko Amesara, spokeswoman for Daiei Inc., another major supermarket chain.

The country is also expecting an electricity shortage, because 11 nuclear power plants in northeastern Japan, which furnish much of the power for the Tokyo area, have been shut down after the quake.

The government has asked people to turn off their lights as much as possible and ordered partial blackouts in some cities. Tokyo commuter trains have been more packed than usual during rush-hour, because major railways are running on reduced scheduling to save power.