BEIJING — Officials in the western Chinese region of Xinjiang said Monday that an antiterrorism crackdown that began in late May had resulted in the smashing of 32 terrorist groups and the sentencing of 315 people to prison terms, death row or other punishment, according to state news reports.

The sentences were handed out in 120 separate court cases, according to a lengthy report posted on the website of Legal Daily. In their investigations, the police confiscated 264 explosive devices and more than three tons of explosive material, the report said. Details of the official announcement were also reported by Xinhua, the state news agency.

Details in the reports could not be independently confirmed, and official versions of violent events in Xinjiang are often murky. The region has a significant ethnic Uighur population that is mostly Muslim and whose members often complain of discrimination and heavy-handed restrictions from the ruling Han, the dominant ethnic group in China. Some Uighurs advocate an independent homeland and the number of clashes has been growing in recent years between Uighurs and Han-led security forces, and increasingly with Han civilians, too.

The state news media reported Saturday that police officers had shot and killed 13 attackers who drove a vehicle into the police headquarters of Yecheng County in Xinjiang and set off explosives. The Legal Daily reported that recent violence, “fully exposes the brutal nature of the frantic terrorists who have no hearts, expresses the sheer complexity of Xinjiang’s antiterrorism and stability maintenance situation, and shows there is a long way to go in severely cracking down on terrorists and criminals.”