BEIJING, May 7 (Xinhua) -- Officials in east China's Zhejiang Province will now be demoted or even fired if they fail to properly enforce family planning policies in their organizations, according to a new regulation issued by the provincial government.

"Local officials whose precincts have not passed an annual assessment on the work of family planning and whose subordinates defy the family planning policy by having more children than recommended will not be promoted," said the regulation.

It said officials who fabricated population data in order to pass assessments will also face punishment.

Officials will be demoted or dismissed if they fail to pass family planning performance assessment twice in their term.

As the world's most populous nation, China has been following a strict family planning policy since the 1970s to contain its population growth.

The policy encourages late marriages and late childbearing, and limits most urban couples to one child and most rural couples to two.

The family planning policy is credited with preventing 400 million new births in the country.