Local Chinese officials are blaming Muslim extremists trained in Pakistan for the latest violence in China's restive Xinjiang region.

Authorities in Kashgar city said Monday that a group of what they called “armed terrorists” stormed a city restaurant Sunday, killing the owner and a waiter before setting the building on fire. The local authorities said the attackers then began randomly stabbing people in the street, killing four and wounding at least 12.

In a posting on the city government's website, the officials said police killed five of the attackers and captured four others. The officials said the detainees have admitted that at least one of the group's leaders trained in making explosives and firearms at camps of the East Turkestan Islamic Movement in Pakistan before infiltrating back into China.

The East Turkestan Islamic Movement is a banned organization that seeks independence for Xinjiang, where the native ethnic Uighur population has long chafed under Chinese rule. The Kashgar officials offered no evidence for their claims, which could not be independently confirmed.

Sunday's attack was the latest in a series of violent incidents in Xinjiang, including one Saturday in Kashgar in which at least seven people died and more than 20 were injured.

The official Xinhua news agency said that killing spree began when two men hijacked a truck and killed the driver. It said they then drove into a crowd and jumped out, randomly hacking at bystanders.

Two weeks ago, officials reported killing 14 rioters who attacked a police station in Hotan city. A Uighur exile group disputed the official account, quoting witnesses who said police had fired into a crowd of peaceful demonstrators.

Tensions have been high in Xinjiang since ethnic riots two years ago between Uighurs and Han Chinese that left about 200 people dead.