The Tokyo Metropolitan Government amended its rules on noise pollution on Wednesday in an effort to make it easier for nurseries to open in the capital, where the number of children yet to find a day care facility is the largest among all prefectures.

The amendment exempts noise made by preschool children from the municipality's environment-maintenance bylaw, which requires that noise not surpass specified levels.

The move comes on the same day that a nursery was supposed to open in the city's Meguro Ward. However, plans for that facility were suspended indefinitely due to opposition from local residents, who feared being disturbed by noise from the facility.

The case of the Sakurasaku Hoikuen nursery highlights one of the many obstacles hindering efforts to encourage mothers to return to the workforce. Many parents have difficulty finding day care amid a serious shortage in the sector.

Encouraging more women to go back to work after pregnancy is a key to Prime Minister Shinzo Abe's efforts to revitalize the economy, which suffers from a dwindling workforce amid a low birthrate and longer life expectancy.

Blossom, a Tokyo-based company, planned to use a building near Toritsudaigaku Station on the Tokyu Toyoko Line to provide day care services for up to 62 children.

Meguro Ward awarded the firm accreditation as a day care provider in October. The company planned to open the facility on April 1.

But when Meguro Ward office, which is responsible for assigning children to accredited nurseries, ran a notice in its November bulletin inviting parents to apply for places, it prompted a backlash from some local residents.

A petition to halt the planned day care drew over 200 signatures, prompting the company to suspend its plan even as applications for places began to come in, said a Blossom spokesman.

"We meet all necessary requirements to operate, and we aren't required to obtain residents' approval either," the spokesman said. "But we felt we needed to suspend it, because we take a good relationship with residents seriously."

The company subsequently held a meeting with the residents to let them express their concerns.

The residents, many of whom are elderly, mainly spoke of noise concerns. Some said they were worried about parents blocking a narrow alley in front of the building with cars or bicycles.

Complaints about noise caused by children have come under the spotlight in recent years in Tokyo.

Last October a man was arrested for allegedly threatening a father with a hatchet near a nursery in the neighborhood of Kokubunji, apparently angered by noise from the facility. The father had come to collect his child.

In 2012, a residents' group in Nerima Ward sued a day care operator, seeking an injunction to halt noise from the facility, citing the environment-maintenance bylaw.

In the residential district of Setagaya, nearly 20 percent of applications to build new child care centers were delayed following complaints by residents, the mayor told local media.

The problem is exacerbating an already-dire shortage of facilities for young children throughout Japan, hampering efforts to tempt the country's well-qualified but under-employed women back into the workforce.

About 43,000 children are waiting for vacancies in nursery schools in Japan, 12,000 of them in Tokyo alone, the labor ministry says.

Already, a quarter of Japan's population of 127 million is aged 65 or over. With little in the way of immigration and a very low birthrate, that proportion is forecast to rise to 40 percent over the coming decades.

That is creating shortages in the labor market and piling pressure on an already-strained social welfare system in which fewer workers are supporting ever-more pensioners.

A lack of child care not only prevents mothers from returning to their jobs to bulk up the workforce, but also plays a part in dissuading them from having more children, thus worsening both problems.

Experts note that the issue is self-perpetuating because an aging and declining population becomes less tolerant of children as it is exposed to fewer of them.

Information from AFP-JIJI added