Nine people who attacked a police station and two auxiliary police officers who tried to fight them off have died in a troubled town in Xinjiang, north-western China, according to officials.

Saturday's violence came seven months after 21 people died in clashes in the same place – Bachu county, near Kashgar – in the deadliest single incident in the region since 2009.

Last month, three attackers ploughed a vehicle through crowds at Tiananmen Square, in the heart of Beijing, killing themselves and two tourists.

Police have detained five people in connection with the Tiananmen attack and described it as a terrorist plot, blaming the East Turkestan Islamic Movement, while a former official from the driver's home town suggested it might be connected to his anger at a raid on a mosque.

The Xinjiang government said in a statement on its microblog that assailants wielded knives and axes as they attacked the police station in Serikbuya township late on Saturday afternoon. It added that the men were shot dead by police and two officers were also injured in the clash.

The state news agency Xinhua named one of the assailants as Abla Ehet, apparently a Uighur name.

China argues it has invested heavily to develop the region and improve living standards and blames separatist terrorists for stirring up unrest. But many in Xinjiang's large Uighur Muslim population are increasingly resentful of controls on their culture and religion and high levels of Han migration. Some seek independence for what they call East Turkestan.

David Tobin, an expert on the region at the University of Glasgow, said incidents involving Uighurs tended to be immediately presented as terrorism by authorities but were often localised. "It's related to the politics of and economics of the region, but the incident itself is sparked by a corrupt official or someone not being treated right," he said.

Radio Free Asia said witnesses told them that a group of residents pleaded with police not to kill the young men, saying they should shoot them in their limbs and capture them alive.

A Swedish-based exile activist, Dilxat Raxit, alleged that security forces have increasingly been shooting to kill at the scene rather than capturing people.

"Before, they'd put them on trial. You could argue about the fairness of the trial, but at least they were alive. Now, they're just killing them outright," he told Associated Press.

In April, officials said 15 police officers and community workers were killed and six suspects shot dead after community workers were taken hostage when they found knives at a house and called for help. A gang hiding at the house then attacked police and officials, killed the hostages and set the house on fire.

In August two men were sentenced to death and three others jailed over the attacks.