Chinese state media say the government in the western region of
Xinjiang has declared a curfew following ethnic unrest that has
paralyzed the main city of Urumqi.
China's top official in Urumqi, Communist party leader Li Zhi, said Tuesday authorities also are blocking Internet and mobile phone service in parts of the city in order to prevent further unrest.
Chinese foreign ministry spokesman Qin Gang said "foreign forces" are using those services to instigate violence.
Both officials specifically blamed U.S.-based Uighur exile Rebiya Kadeer for masterminding Sunday's rioting that left at least 156 people dead.
In further unrest Tuesday, Muslim Uighursand Han Chinese faced off with riot police in separate incidents.
Police first confronted about hundreds of mostly female Uighur protesters, who said members of their families had been arbitrarily arrested, after Sunday's riots.
Later in the day, riot police fired tear gas to disperse thousands of Han Chinese protesters who took to the streets armed with makeshift weapons, including clubs, shovels and knives.
The crowd smashed shops and food stands operated by Uighurs. Communist Party chief Li Zhi arrived on the scene, where he condemned Rebiya Kadeer in a speech to the crowd.
There were also reports that Uighur protests were held in the city of Kashgar, near Xinjiang's border with Pakistan.
The United Nations' High Commissioner for Human Rights, Navi Pillay, urged Chinese authorities and ethnic groups in Xinjiang to refrain from further violence.
Tensions between Han and Uighurs came to a head last month, after a false rumor spread throughout a toy factory in Guangdong that Uighur workers raped two Chinese girls. A huge fight broke out, and two people were killed.
The official Xinhua news agency said Tuesday that police have arrested 15 people in connection with the racially-charged brawl, including two suspected of spreading rumors on the Internet.
State-run media said police have arrested 1,434 suspects in the deadly ethnic clashes, which injured more than 1,000 people on Sunday.
As with last year's protests in neighboring Tibet, Chinese state media coverage has focused on ethnic Han victims.
Uighur groups say the violence is a result of pent-up frustration with what the mainly Muslim Uighurs say is excessive control over their lives by Han Chinese -- China's majority ethnic group.
Uighur dissident Wu'er Kaixi, who was one of the student leaders of the 1989 Tiananmen Square demonstrations, told reporters Tuesday that Uighurs face widespread suppression and discrimination in China.