The chemical weapons that Japan's imperial army forces abandoned in China during the closing days of World War II are a ticking time bomb.

Periodically, one of the weapons leaks its deadly toxic load with tragic results. Now, after years of attempting to clean up the mess, Tokyo is gearing up to build a facility to safely dispose of the ordnance.

The project is monumental, and technically, Japan is obliged to finish the job by April 2007.

Since 1991, Japanese inspection teams have unearthed about 37,000 chemical munitions at 30 sites in Guangdong and Heilongjiang provinces. The weapons remain in China, awaiting disposal.

The disposal facility will be built in Haerbaling, Jilin province, which experts estimate is littered with about 10 times as many abandoned chemical weapons as Japan has already disposed of.

A 1996 study by Japanese officials estimated that 670,000 chemical weapons were dumped in Haerbaling. The figure was lowered to between 300,000 and 400,000 in a 2002 study.

No disposal work has begun in Haerbaling, in part because of the daunting scale of the problem.

With China's approval, Japan intends to begin constructing a massive collection and disposal facility there to begin the dangerous and delicate task of destroying the volatile weapons.

Government officials say they hope the disposal work will help to improve bilateral relations much damaged by Prime Minister Junichiro Koizumi's annual visits to Yasukuni Shrine, where Japan's war dead are honored along with 14 Class-A war criminals from World War II.

Cabinet Office Vice Minister Takeshi Erikawa visited China in October to meet with Wu Dawei, China's vice foreign minister. Together, they emphasized the need for an early start on construction.

Once Beijing gives the formal go-ahead, work to clear the site will begin early next year, sources said.

Even though the number of abandoned chemical weapons is smaller than was once believed, Japanese officials say the disposal work presents an enormous challenge.

Unearthing the dangerous weapons will be done with a machine that is operated by remote control. The proposed facility will comprise several buildings, one of which will be used to X-ray recovered weapons. The facility will also have storage and disposal sites.

The plan calls for a daily disposal rate of 640 to 650 weapons.

Weapons stored in remote areas would be transported to Haerbaling on special trailers.

Time is of the essence. Under the United Nations Chemical Weapons Convention, Japan must dispose of all the chemical weapons it left in China by April 2007.

Although officials have said they will make every effort to meet that deadline, more realistically, an extension will likely be requested from the U.N. Organization for the Prohibition of Chemical Weapons next April, a year before the deadline.

Government officials estimate total costs at about 200 billion yen to construct and operate the facility for a four-year period starting in 2006.

Disposal of abandoned chemical weapons is one of the few areas in which Japan and China have agreed to cooperate.

In his October meeting with Erikawa, Wu praised the deal. "We highly regard Japan's efforts and stance on this issue," he said.

However, with top-level dialogue between Japan and China currently at a standstill, there are no prospects that other bilateral issues, such as the dispute over China's development of gas and oil fields under the East China Sea, will be settled soon.

A high-ranking Cabinet Office official said, "Both sides recognize that (the disposal) project is a constructive and important one that is oriented toward the future."

Chinese officials are keen to get rid of the chemical weapons as soon as possible to avoid further tragedies. In August 2003, one person was killed and 43 injured by poison that leaked from an abandoned chemical weapon at Qiqihar, Heilongjiang province.(IHT/Asahi: November 24,2005)