BEIJING (Reuters) - As the United States debates its gun laws after the Newtown school massacre, China is doing its own political soul-searching after a shocking knife attack on a Chinese elementary school.

On the same day as the Newtown shooting, a crazed man broke into a school building in central China, stabbing and slashing 23 pupils in an attack that, although not fatal, lit up the Internet - but barely registered with official state media.

Instead, media gave top coverage to the U.S. shooting and barely mentioned the Henan school attack, a decision that has drawn sharp criticism of the ruling Communist Party's readiness to reflect on the ills of U.S. society but not on China's own.

"On the same day as the U.S. shooting, 22 children were slashed at the school in Henan, but mainstream media were virtually mute on this. Are the lives of Chinese children worthless to them?" a microblog user wrote in one of many such posts.

According to China Digital Times, a website following social and political developments in China and run by the University of California, the government's central propaganda department ordered all official media to downplay the Henan attack.

The Internet criticism of official media coverage follows the installation last month of a new Communist Party chief, Xi Jinping, who has signaled a more open style of leadership and told the media not to shy away from focusing on genuine news.

However, last week's Henan attack has been largely missing from Chinese newspaper and TV reports. The Xinyang Daily, whose circulation area includes the school, devoted its page-one story on Monday to lauding the local education system without mentioning the attack, according to the Global Times newspaper.

The Xinyang paper later apologized for the story.

(Reporting by Terril Yue Jones and Sally Huang; Editing by Ron Popeski)