HONG KONG — From Urumqi in China's northwestern corner to Hong Kong in the southeast, people across China bowed their heads(低头) at 2:28 p.m. local time on Monday to observe three minutes of silence to mourn the deaths of （默哀三分钟）more than 30,000 people in the earthquake a week ago in Sichuan province.

Flags flew at half mast across the country（全国降半旗）, the beginning of three days of mourning. In the earthquake zone, rescuers paused in their efforts to find the living so as to remember the dead.

Aftershocks（余震）, rain and the continued instability of hillsides in Sichuan province have posed a serious threat for relief workers.

In Hong Kong, a former British colony where a strengthened sense of solidarity with mainland China has emerged since the earthquake, the stock exchange halted trading for three minutes（股票交易所停止交易三分钟）. Chief Executive Donald Tsang （特首曾荫权）and his cabinet stood in black suits in front of the central government offices to mark the moment. At Hong Kong's legislature, lawmakers joined a group of schoolchildren to mark the deaths.

While many people in China fell silent, the streets were anything but quiet（街上一片寂静）, as air raid sirens wailed to mark the moment. Stock exchanges in Shanghai and Shenzhen also halted trading during Monday's three minutes of mourning.

The American embassy in Beijing （北京的美国大使馆）and the American consulates in Hong Kong and across mainland China began flying the American flag at half-mast on Monday morning for three days of mourning as well, out of respect for China's loss.

In Hong Kong, during the minutes of silence, the giant television screens in Hong Kong's Causeway Bay(铜锣湾), the center of the city's best-known shopping district, showed images of people across China in mourning.