Two men were injured yesterday when a 6.3 magnitude earthquake hit a mining area in the Haixi Mongolian and Tibet autonomous prefecture of Qinghai province, the local government said on its website.

The quake happened at about 9:22 am, and its epicenter was in Da Qaidam, a sparsely populated town of about 16,000 Mongolian, Tibetan, Muslim Hui and Han people, the prefecture government said.

According to the People's Daily's website, more than 25 aftershocks were reported before noon in the area, with the strongest being a magnitude 5, which struck at about 11:44 am.

The two injured men were among several groups of miners working in the area at the time of the tremor, the government report said.

Zhang Jianchang, an official with the Qinghai earthquake administration, told China Daily: "As far as we know, there were about 200 miners working underground at the time, but they are all now safely back above ground. There have been no reports of any casualties.

"Da Qaidam is a remote area with a low population density of one person per sq km and seven mines. The earthquake is unlikely to have caused any serious damage."

Zhang was speaking prior to the announcement of the two injuries on the local government website.

It also said cracks had been found in the walls of several houses in Da Qaidam, and in about 20 homes in the city of Delingha, in which Da Qaidam is located.