China's State Bureau of Surveying and Mapping (SBSM) has published a list of 46 domestic websites that offered online mapping services without obtaining permission, warning they would be punished if they fail to obtain approval after July 1.

Those websites include www.map.homelink.com.cn, www.beijing.map.8684.cn and other websites from which many Chinese Internet users search for bus routes or find the locations of real estate projects, according to a notice posted on SBSM's website Monday.

The SBSM did not elaborate on what punishment the website operators might face.

China launched a nationwide campaign to eliminate illegal online mapping services in March.

Administered by a coordinating board made up of 13 ministry-level agencies headed by the State Bureau of Surveying and Mapping, the campaign is expected to address major violations, including unauthorized disclosure of confidential information on the maps and mistakes in drawing the country's borders, especially on islands and coastal areas.

China introduced a new licensing system for Internet mapping services last May and required all providers to acquire a license before the end of March.

As of mid-February, licenses had been granted to 105 websites across the country, including search giant Baidu, leading portal Sina, Nokia and China Mobile, the country's largest telecommunications operator.