A 5.3-magnitude earthquake hit a remote county in northwest China's Xinjiang Uygur Autonomous Region Wednesday, causing a car pileup which left five injured.

The quake jolted Toksun County of Turpan Prefecture at 9:53 a.m., according to the China Earthquake Network Center.

Toksun County is about 160 km from Urumqi, the regional capital.

The quake caused several big rocks to roll down a mountain in the neighboring Dabancheng District, and onto a road forcing a driver to slam on his car brakes leading to a 17-car pileup, said Zhang Qirui, an official with the district's road bureau.

Five people were hurt in the collision, among whom two were severely injured, he said.

The epicenter was monitored at 43.0 degrees north latitude and 88.3 degrees east longitude with a depth of about 5 km, the center said.

The quake was followed by two large aftershocks, measuring 4.2- and 4.1-magnitude and occurring at 9:54 a.m. and 10 a.m., respectively, according to the center.

A specialist with Xinjiang's earthquake administration said further earthquakes in the region are unlikely.

"Quakes over 5-magnitude have rarely been reported in Toksun County over the past 70 years. Citizens do not need to worry," the specialist said.

Railway services on two important routes were suspended for two hours for safety checks.

Passenger and cargo trains were halted in the Urumqi-Turpan section of the Lanxin Railway, a pivotal link between Urumqi and the city of Lanzhou in northwest China's Gansu Province, and the Turpan section of the Nanjiang Railway, which links Turpan with the city of Korla in southern Xinjiang, the Urumqi Railway Bureau said in a press release.

Service resumed at around 12:30 p.m. after safety checks were completed, it said.

More than 800 students in Toksun County were taking a national college entrance exam at two local schools when the quake struck, said Gu Kejun, an official with Turpan's education bureau.

"About halfway into the test, my desk shook and I was scared. We were then told to leave," said Xia Daiti, a student who was taking the test at Toksun County's No. 1 Middle School.

The students were given an additional 70 to 90 minutes to finish the exam after being evacuated, Gu said.