Hong Kong (CNN) -- A local court in the far western Chinese province of Xinjiang has sentenced to death a Uyghur man who it says led an attack in a busy street last month that left 15 people dead, Chinese state media reported.
The World Uyghur Congress, an exile group, condemned the sentence and contested the Chinese authorities' account of the violence. It also questioned whether the defendant, Abdukerem Mamut, received a fair trial.
The court in the Xinjiang Uyghur Autonomous Region convicted Mamut of "organizing and heading a terrorist group, and intentional killing" and sentenced him to death on Monday, the Global Times, an English-language newspaper run by the Communist Party, reported.
It said Mamut and other members of the group killed 15 people and wounded 14 others "with axes and knives" in Yecheng County on February 28. The police detained Mamut at the scene and shot dead the other attackers, according to the report.
The Chinese authorities said four policemen were wounded and one local security officer was killed in the clash.
But the World Uyghur Congress offered a different version of events, saying that according to unidentified local people, the violence left 10 Uyghurs, seven members of the security forces and five other people dead, as well as 11 Uyghurs wounded.
The Chinese authorities have often blamed militants of Uyghur descent for outbreaks of violence in Xinjiang in recent years, labeling them terrorists.
Uyghurs are ethnic Turks who are linguistically, culturally and religiously distinct from China's majority Han population.
The quick conviction and sentencing of Mamut in connection with the violence "casts serious doubts on the legitimacy of the trial, and we do not believe that it met international legal standards," Rebiya Kadeer, the president of the congress, said in a statement published Tuesday on the organization's website.
""The death sentence is not only used arbitrarily against Uyghurs who dare to stand up for their basic human rights, but also to intimidate the Uyghur population," Kadeer said.
Xinjiang was rocked by the worst violence in decades in July 2009 when rioting between Uyghurs and Han Chinese left nearly 200 people dead and 1,700 wounded in the regional capital, Urumqi.
Last year, the authorities carried out a two-month security operation, which ended in October, against violence, terrorism and radical Islam across Xinjiang, a resource-rich region, which borders Pakistan, Afghanistan and several Central Asian states.
The tightened security measures included 24-hour security patrols of troubled areas, identity checks and random street searches of people and vehicles.
The crackdowns on Uyghurs in the region have continued, the Uyghur congress said Tuesday, reporting a rise in arbitrary detentions and noting a string of clashes between the authorities and the local population. The Chinese authorities in Xinjiang said in January that they planned to recruit 8,000 extra police officers.
Uyghur activists say the crackdowns heighten anger among local Uyghurs who already accuse the government of religious and political repression.
Uyghurs also say they feel economically disadvantaged as a thriving Han population continues to move into the region.
CNN's Jethro Mullen and Judy Kwon contributed to this report.