An aftershock measuring 6.4 on the Richter scale jolted Qingchuan county in southwest China's Sichuan Province on Sunday afternoon.

The strongest aftershock since the 8.0-magnitude quake of May 12 hit at 4:21 p.m. and was felt in many parts of the province, including the provincial capital Chengdu, said Hou Jianmin, a senior engineer with China National Seismic Network.

The network has located the epicenter of the aftershock at 32.6 degrees north latitude and 105.4 degrees east longitude in Qingchuan county, which sits on the northeastern border of Sichuan Province and neighbors Gansu and Shaanxi provinces in northwest China.

"We were at a temporary office of the local government and all of a sudden, everything in the room began rocking back and forth," said a CCTV reporter in Qingchuan. "The computer almost slipped from the desk and tiles fell from the roof. Everyone panicked."

A store keeper in Mianyang City said his store creaked in the aftershock and everyone fled. "We couldn't even stand still," he said.

"I could feel the ground and the mountain were shaking in the tremor," said a CCTV reporter in Beichuan County, which suffered the most from the May 12 quake.

Xinhua reporter Hai Mingwei said a plastic water bottle, placed upside down on the floor standing air conditioner of his home in downtown Chengdu, fell in the aftershock. "Though thousands of aftershocks were felt since May 12, this is the first time the bottle fell," he said.

After the devastating quake, many locals have put bottles in their house as a "forecaster" of aftershocks.

The aftershock was said to have lasted for about a minute and many high-rises in Chengdu rocked slightly.

A Beijinger said he felt the aftershock, too, from his 25th floor office. Residents on lower floors did not feel the tremor.

The tremor was also felt in Xi'an, capital of the northwestern Shaanxi Province, where citizens fled homes and offices to seek shelter in open spaces.

A hotel worker in Shaanxi's Hanzhong City said she felt clearly the aftershock was strong and "next only to the May 12 quake".

About 40 minutes before the aftershock, local residents said the weather in Hanzhong City became overcast and high winds began to blow. Mobile communication was in failure for a while.

Several cities in Gansu Province were affected by the tremor, including the provincial capital Lanzhou and Wudu, Kangxian and Wenxian counties.

Citizens in the northern Shanxi Province said the aftershock did not cause much fear. Xinhua reporter Wang Zhaokun said he felt tremor and saw the pendant lamp swinging in his 26th floor apartment in downtown Taiyuan.

Nearly 8,000 aftershocks have been reported in Sichuan Province following the May 12 earthquake. The death toll has topped 62,664 as of Sunday, including 62,161 in Sichuan alone.

(Xinhua News Agency May 25, 2008)