By Lucy Hornby

CHENGDU, China (Reuters) - Tens of thousands of panicked Chengdu residents rushed into the city's streets early on Tuesday, spooked by a Chinese provincial television report predicting another earthquake.

Cars jammed roads leading out of the city and people clogged the pavements, carrying pillows and blankets and heading for open ground or parks.

China is observing three days of national mourning a week after a 7.9-magnitude earthquake killed nearly 34,000 people, mostly in the mountainous areas north and west of Chengdu.

Provincial television and radio reported that a 8-magnitude earthquake would strike Sichuan overnight, and that 6-magnitude tremors would shake Chengdu.

"They quoted a government department, so everyone's heading for clear space. I'd be careful if I were you," called a young man surnamed Huang.

A large aftershock shook Chengdu on Saturday night, and killed three people and injured 1,000 others in Sichuan province. The aftershock, and a powerful thunderstorm that followed, has set people's nerves on edge.