BEIJING - The Ministry of Land and Resources and the Ministry of Supervision publicized a list on Thursday of 73 officials from 31 cities and counties who had been punished for various infractions connected to the illegal use of land.

"In all these cities and counties, 15 percent of new land development was illegal, according to 2009 satellite images and the management of the market for land transfers has been disorderly," said Li Jianqin, director of the law enforcement and supervision department at the Ministry of Land and Resources.

Li told China Daily the 73 officials received administrative punishments that included warnings and demotions. He said no officials at the provincial level were involved.

It was the first time that such a large group of officials had been punished for their involvement in the illegal use of land.

The 31 cities and counties were largely in less-developed parts of China and first-tier cities such as Beijing, Shanghai, Guangzhou and Shenzhen were not among them.

"The punishments will definitely sound an alarm bell among local authorities and strengthen their land protection measures," Li said.

He added that the proportion of illegally used land was around the benchmark 15 percent of total land used for development in the affected areas.

In May 2008, the Ministry of Land and Resources, the Ministry of Supervision and the Ministry of Human Resources and Social Security jointly issued a document that declared an accountability system would be launched to protect the shrinking reserves of arable land.

According to the document, the authorities will look at satellite images from the previous year and compare them to the latest satellite images. If more than 15 percent of newly developed land has been illegally developed from supposedly protected farmland, the officials responsible for the illegal land grabs will be punished and could even be dismissed from their posts.

On Dec 16, the heads of 12 cities and regions known to have serious problems with the illegal use of agricultural land were invited by the Ministry of Land and Resources for a face-to-face chat about how they could strengthen their land protection efforts.

However, after that meeting, the deadline by which local authorities' records in land use were supposed to have been made public - February - was pushed back to July, triggering criticism from the public.

Li said the reason for the delay was to allow time to double-check the facts before handing out any punishments.

Yan Jinming, a land management professor at Renmin University of China, told China Daily that the delay was indicative of the pressure the two ministries are under as they try to crack down on the illegal use of land, which is common among local governments.

He said the fact that no first-tier cities were among the local authorities being criticized and punished shows that the ministries are taking a cautious approach.

"Anyway, this large list of authorities with illegal land use problems is the first of its kind and will alarm all local authorities," Yan said.

According to statistics from the Ministry of Land and Resources, as of 2009, more than 2 million hectares of damaged land had been reclaimed for farming. However, during the same period, 8.67 million hectares of farmland was lost - either to construction or because of natural disasters.

The percentage of land in China being used illegally for development has been falling. In 2006, 48.5 percent of development sites were on illegally used farmland. That number fell to 11.7 percent in 2009.

Between January and June, there were around 23,000 cases of illegally used land involving 9,067 hectares. The amount of land was less than the size of illegally used land during the same period in 2010.

In order to better protect the country's arable land, China is increasing its satellite surveillance of the country. In 2000, 66 cities, regions or counties were being monitored by satellite. In 2009, that number had risen to 2,895.