Forecast of a strong aftershock in southwest China's Sichuan Province late on Monday has prompted panic among the local residents as well as the neighboring Chongqing Municipality and Guizhou Province.

The provincial seismological bureau in Sichuan forecast on Monday night that an aftershock between six to seven on the Richter scale was likely to rock Wenchuan County, about 159 kilometers from Chengdu and epicenter of last Monday's devastating quake, on Monday or Tuesday, and warned local governments and people to be prepared for emergencies.

The aftershock warning came a week after the 8.0-magnitude earthquake that killed more than 34,000 people. The final death toll was expected to reach 50,000.

The forecast, which was repeated via TV and radio in Sichuan, sent many citizens in Chengdu away from home. Private cars trying to get out of the city center packed urban roads between Monday night and Tuesday morning. The congestion was worsened by vehicles that lined up in front of gasoline stations waiting to fill up their tanks.

Many citizens in Chengdu spent a sleepless night by sitting up and getting prepared to escape or setting up tents in the open air.

Residents of the outer districts and counties also fled home amid the quake scare.

Despite the panic, many people praised the government's sense of responsibility in publishing the aftershock forecast. Some, however, complained it had come "too late".