A senior Chinese environmental official says air pollution readings posted by foreign embassies are an unacceptable interference in Chinese internal affairs.

The comments made Tuesday by Vice Environment Minister Wu Xiaoqing were a clear reference to the air quality readings posted regularly on the Twitter page of the U.S. Embassy in Beijing.

Wu said only the Chinese government has the authority to publish such readings. He said pollution figures posted by foreign embassies and consulates are illegal and should stop.

The U.S. embassy posts hourly air-quality data on its popular Twitter feed, which boasts over 19,000 followers. The U.S. consulate in Shanghai has a similar service.

The embassy feed was set up in 2009 following widespread complaints that official government readings were understating pollution levels in the smog-filled capital city.

In January, Beijing authorities promised to start publicizing more precise data on the city's air quality. But there are often large differences between the official and U.S. readings, which Chinese government officials have criticized as being “unscientific.”