About 60,000 people in Wenchuan county, the epicenter of a strong earthquake that struck southwest China Monday afternoon, were still out of reach on Tuesday morning while the county seat reported 57 deaths and more than 300 injuries.

"I am much worried! I am much worried!" said He Biao, deputy secretary-general of the government of Tibetan-Qiang Autonomous Prefecture of Aba, Sichuan Province, over a telephone interview with Xinhua.

The Wenchuan county and Aba prefecture governments so far had not received any phone call from the Yingxiu, Sanjiang and Xuankou towns and Wolong district, which have a combined population of 60,000, according to He.

Wang Bin, Communist Party secretary of Wenchuan County told Xinhua on Tuesday morning that the county seat had so far recorded 57 deaths and more than 300 injuries.

"This is only rough number of casualties at the county seat. The figure is highly possible to rise as the casualties in the mountainous area is not available," said Wang.

More than 30,000 residents are staying outdoors at the county seat despite heavy rains, he added.

Wenchuan, with a population more than 105,000, was hit by a 7.8-magnitude earthquake at 2:28 p.m. Monday. A number of aftershocks have been recorded.

Wang appealed for emergency aid via a satellite phone early Tuesday, after the county was cut off from the outside world.