Beijing - Amnesty International on Wednesday criticized China for its "hasty" execution of nine people convicted of murder, arson and other violent crimes during ethnic rioting in the far western province of Xinjiang in July.

"In hastily executing these individuals after unfair trials, the Chinese authorities are perpetuating some of the very injustices that helped trigger the outburst of violence in the first place," Roseann Rife, deputy director of Amnesty International's Asia-Pacific programme, said in a statement.

Eight members of China's mainly Muslim Uighur minority were executed last week, along with one Han Chinese man convicted of murdering Uighurs, according to state media.

They were among 21 people tried and sentenced last month for their part in the rioting in the regional capital, Urumqi.

London-based Amnesty noted that the closed trials lasted less than one day and that promises by regional officials to sentence to death "brutal criminals" involved in the rioting had made it "very difficult for a fair trial to be conducted."

Chinese authorities also pressurized specialist rights lawyers based in Beijing not to represent the defendants in Urumqi, the group said.

"Given the large number of detentions reported by Chinese officials in connection with the unrest, dozens more trials could take place, possibly leading to more executions," Rife said.

"The Chinese government must ensure that that the trials are conducted in line with international human rights standards, with transparency and without recourse to the death penalty," she said.

On Tuesday, the World Uighur Congress said police had detained another 257 Uighurs in three areas of Xinjiang since the start of November.

Dilxat Rexiti, a Munich-based spokesman for the World Uighur Congress, also condemned last week's executions and said the eight Uighurs were not even allowed even to see their families before execution.

The deadly rioting in Urumqi left 197 people dead and about 1,600 injured in early July, according to the government.

Uighur exile groups claimed, however, that up to 800 people died in Urumqi, many of them Uighurs shot or beaten to death by police.

The rioting apparently began after a protest over the deaths of two Uighurs in the southern city of Shaoguan. The killings escalated into clashes with police and attacks by Uighurs against Han residents of Urumqi. (dpa)