BEICHUAN, May 18: A fresh tremor in southwestern China killed three people on Sunday, injured 1,000 others and sent thousands of people already traumatised by last week’s massive earthquake fleeing from their homes and into the streets.

The tremor, the strongest aftershock since the May 12 earthquake, hit Jiangyou city in Sichuan, Xinhua state news agency said, on the eve of three days of national mourning for the dead that now stands officially at 32,500.

The fresh tremor, which measured 5.7 in magnitude, brought down a large number of houses, damaged 377km of roads and six bridges, rescue authorities said on Sunday night.

In the provincial capital, Chengdu, some 200km south of the epicentre, thousands fled swaying buildings, Xinhua said.

More than six days after the main quake of 7.9 magnitude rattled Sichuan province, authorities are worried by the aftershocks and the build up of water in blocked rivers and have tried to stop people from entering the affected area.

Xinhua said the most dangerous mass of water was only about 3km upstream from Beichuan town where rescue workers saved a man on Sunday from under the remains of a hospital.

China says it expects the final death toll to exceed 50,000. About 4.8 million people have lost their homes.

Three days of national mourning were declared from Monday, with flags flying at half mast, public entertainment suspended and a three-minute silence observed to mark exactly one week since the quake, the government website www.gov.cn said.

—Reuters