Armed Police watch as China's national flag flies at half-mast at a square in Xi'an, northwest China's Shaanxi Province, May 19, 2008. China on Monday begins a three-day national mourning for the tens of thousands of people killed in a powerful earthquake which struck the country's southwestern regions on May 12.

Armed Police salute as China's national flag flies at half-mast at a square in Xi'an, northwest China's Shaanxi Province, May 19, 2008. China on Monday begins a three-day national mourning for the tens of thousands of people killed in a powerful earthquake which struck the country's southwestern regions on May 12.

China's national flag flies at half-mast in front of Zhejiang People's Great Hall in Hangzhou, east China's Zhejiang Province, May 19, 2008. China on Monday begins a three-day national mourning for the tens of thousands of people killed in a powerful earthquake which struck the country's southwestern regions on May 12.