Oct. 24 (Bloomberg) -- Aftershocks continued in northwest Japan after a series of earthquakes killed 21 and injured 1,800, forcing thousands more to seek shelter in the deadliest temblor since 1995.

Highways caved in, railway lines buckled and bridges collapsed along the fault lines. Seven earthquakes and as many as 280 aftershocks may cause landslides in areas where Typhoon Tokage -- the worst cyclone to hit Japan since 1991 -- poured as much as 500 millimeters (19.7 inches) of rain last week, a Japan Meteorological Agency spokesman said. The agency warned on its Web site that additional quakes may occur this week.

Prime Minister Junichiro Koizumi and his cabinet will get a report on relief measures at 8:20 p.m. local time, Kyodo News service said, citing Chief Cabinet Secretary Hiroyuki Hosoda, the government's official spokesman.

``We will certainly compile the necessary budget,'' Koizumi told reporters at his official residence in Tokyo, according to Kyodo. Japan's central government spending for the year ending March 31, 2005, totals 82.1 trillion yen ($765.43 billion).

Additional money may be needed to pay for damage from 10 typhoons that have hit Japan this year. Natural disaster claims in Japan this year totaled an estimated 368 billion yen as of Oct. 1 among 22 companies, according to the General Insurance Association of Japan.

`Utmost Effort'

``The government will unite to make the utmost effort to restore disaster-affected areas,'' Hosoda said, according to Kyodo. Yoshitaka Murata, the disaster-management minister, toured affected areas by helicopter as head of a government task force and will attend the Cabinet meeting, Kyodo said.

More than 60,000 people were in shelters, Kyodo said, citing local police and fire agencies.

The quakes struck a rural area near the west coast of Japan's main island of Honshu, 200 kilometers (125 miles) north-northwest of Tokyo, with the first at 5:56 p.m. local time Saturday registering a magnitude of 6.9 as measured by U.S. Geological Survey seismologists. Six other distinct quakes followed, ranging from 5.1 to 6.1 magnitude. In Tokyo, buildings rocked as the strongest quake registered a magnitude 4, the meteorological agency said.

Shin-Etsu Chemical Co., Matsushita Electric Industrial Co., Sharp Corp. and other companies in the quake vicinity didn't sustain major damage in initial surveys, the Nihon Keizai newspaper reported.

Plants Restart

Electric Power Development Co., or J-Power, as the country's fifth-largest electric generator is known, halted units at two hydroelectric plants in Fukushima prefecture, next to Niigata for checks after a fire broke out.

``Both plants may be able to restart later this evening, although replacing damaged parts at some units may take more time,'' said Hideji Yamada, a spokesman at Tokyo-based J-Power.

The earthquake damaged a transmission line in the area used by J-Power that will also require sections replaced, Yamada said.

About 279,000 customers were without power in Niigata, Kyodo reported. Tokyo Electric Power Co., which has a nuclear power plant in Kashiwazaki Kariwa, near the quake's epicenter, found no serious damage and is running normally, Kyodo said.

Tohoku Electric Power Co. had 129,000 customers without power in Niigata prefecture as of 2 p.m., said Satoru Ishii, a spokesman at the Sendai-based utility.

Not Tonight

``It's going to be impossible to restore power to everyone tonight,'' said Ishii, who didn't know how long it would take before all customers are reconnected.

Teikoku Oil Co., Japan's largest publicly traded natural-gas producer, restarted production from a gas field in Niigata prefecture at midnight local time after it stopped operations following the earthquake., the company said.

The company's gas pipeline network didn't suffer any damage and was operating normally, the company said.

Japan's deadliest quake, in the western port city of Kobe, killed about 6,000 in 1995.

To contact the reporter on this story: Hector Forster in Tokyo at hforster@bloomberg.net.

Last Updated: October 24, 2004 06:50 EDT