There were no immediate reports of major damage or casualties from the quake, which struck at a depth of 6 km (4 miles).

A police office in Hutubi county where the quake struck declined to give details.

A receptionist at a hotel about 2 km (a mile) from the epicentre, reached by Reuters, said the tremors were intense though no buildings had collapsed.

Images posted on the microblog of the state-run China Earthquake Networks Centre showed goods had fallen off shelves at a supermarket and students lined up in rows on a sports field near their school.

The official Xinhua news agency said Urumqi railway authorities suspended services on some lines for safety checks.

Hutubi, a county of about 200,000 people, according to census figures, has a largely ethnic Han population with significant numbers of members of minorities, including from the Hui and Uighur Muslim groups.

Xinjiang, China's largest region, includes large stretches of desert and mountains, and is a major oil, gas and cotton producer. It is also a hub for trade with neighbouring Central Asia.

The US Geological Survey initially reported the quake as magnitude 6.1 and at a depth of 55 km.