As of Sunday, news of the attack had not appeared in the Chinese news media, which frequently delays reporting about unrest in the region for reasons not entirely clear. The authorities make it difficult for foreign journalists to travel to the string of towns and cities in southern Xinjiang where much of the recent bloodshed has occurred.

Violence has been mounting in recent months despite a crackdown on what the authorities describe as Islamic-inspired terrorism. Human rights advocates say harsh security measures and tightened restrictions on religious practices are aggravating discontent among Uighurs, a Turkic-speaking minority who complain about job discrimination and Han migration to the region, which many see as an effort to dilute their ethnic identity.

It was not immediately clear what prompted the attack on the farmers market in Bachu County, but it appears to follow a recent pattern in which Uighur assailants, often using crude weapons, target Han civilians as well as Uighur police officers and government officials. In May, 43 people were killed, including four assailants, in an attack on an outdoor vegetable market in Urumqi, the regional capital of Xinjiang. Many of the dead were elderly Han shoppers.

In July, nearly 100 people died during a clash in Yarkand, not far from Bachu. Among the dead were 37 civilians and 59 others, described by the state media as terrorists, who were shot by the police. Last week, a court in Kashgar sentenced 12 people to death for their role in the violence.

Reached by phone, a front desk clerk at the Lu Xiang Grand Hotel in central Bachu said that there was scant information about what had happened at the market but that people, especially Han, felt wary about walking on the streets. “I just hope the police can guarantee our safety,” she said.