BEIJING - More than 450 people were killed in China's restive mainly Muslim Xinjiang region last year, a rights group said -- with three times as many deaths among members of the Uighur minority than ethnic Han Chinese.
Xinjiang has seen a wave of unrest, labelled by authorities as "terrorism" and blamed on "separatists", which has sometimes spread to other parts of China.
Information in the area is strictly controlled by authorities, and the Washington-based Uyghur Human Rights Project (UHRP) used data from Chinese and overseas media reports for its analysis, giving ranges for most of its figures.
Between 457 and 478 people died last year, it said, adding it had been able to identify 235-240 as Uighur and 80-86 as Han, China's ethnic majority.
The total was more than double that for 2013, when it put deaths between 199 and 237, specifying 116-151 as Uighur and 32-38 as Han.
The rising toll highlights the "excessive force" used by China and a "deterioration in the security environment" since Xi Jinping became Chinese president two years ago, the report said.
The findings were "alarming in a number of aspects", UHRP director Alim Seytoff said.
"It tells us that China's crackdown on Uighurs is only exacerbating the violence....and killing more Uighurs," he said.
The report did not include incidents outside Xinjiang, such as a mass stabbing at a railway station in Kunming last March, when 31 people were killed and four attackers died.
'Lack of transparency'
Chinese authorities usually differentiate between state personnel, civilian victims and attackers in their statements, and the report found that over the two-year period, more alleged perpetrators -- between 229 and 333 -- were killed than official employees (53-108) and civilians (125-194) combined.
"In a troubling number of incidents police killed all alleged 'perpetrators'," the UHRP said in a statement late Tuesday.
"The possibility exists that excessive force and extrajudicial killings are a feature of the Chinese state's security approach to incidents," it added.
Xinjiang witnessed its bloodiest incident since 2009 when 37 civilians and 59 "terrorists" were killed in an attack on a police station and government offices in July in Shache district, known as Yarkand in the Uighur language.
The UHRP report added that "in most likelihood" the number of fatalities over the period "will never be known due to the lack of transparency the Chinese authorities employ when reporting violent incidents".
A separate report released by the Munich-based World Uighur Congress last month said there had been "a dramatic increase in the use of violence" in Xinjiang.
Rights groups say that harsh police treatment of Uighurs and government campaigns against religious practices, such as the wearing of veils, has led to violence.
China defends its policies, arguing that it has boosted economic development in the area and that it upholds minority and religious rights in a country with 56 recognised ethnic groups.
The crackdown in Xinjiang has extended to academics, including prominent Uighur scholar Ilham Tohti who was sentenced to life in prison for "separatism" in September. Several of his students were subsequently tried in secret for the same offence.