China's President Hu Jintao decided to cut short a G8 summit trip Wednesday, after ethnic tensions worsened in China's oil-rich Xinjiang territory, with Chinese men wielding steel pipes and meat cleavers rampaged through the streets and sobbing Muslim women scuffled with riot police. The new violence in the capital of China's Xinjiang province, erupted Tuesday only a few hours after the city's top officials told reporters the streets in Urumqi were returning to normal following a riot that killed 156 people Sunday. The officials said more than 1,000 suspects had been rounded up since the spasm of attacks by Muslim Uighurs against Han Chinese, the ethnic majority. In a rare move, Hu cut short a trip to Italy to take part in a Group of Eight meeting later Wednesday to travel home to deal with the outbreak of violence, the Foreign Ministry said on its Web site. The chaos returned Tuesday when hundreds of young Han men seeking revenge began gathering on sidewalks with kitchen knives, clubs, shovels and wooden poles. They spent most of the afternoon marching through the streets, smashing windows of Muslim restaurants and trying to push past police cordons protecting minority neighborhoods. Riot police successfully fought them back with volleys of tear gas and a massive show of force. Uighurs have said this week's rioting was triggered by the June 25 deaths of Uighur factory workers killed in a brawl in the southern Chinese city of Shaoguan. State-run media have said two workers died, but many Uighurs believe more were killed and said the incident was an example of how little the government cared about them. There was a heavy security presence in Urumqi on Wednesday morning after an overnight curfew in the city of 2.3 million was lifted. Two helicopters flew over the city watching the scene. The ugly scenes over the last several days highlight how far away the Communist Party is from one of its top goals: Creating a "harmonious society." The unrest was also an embarrassment for the Chinese leadership, which is getting ready to celebrate the 60th anniversary of Communist rule and wants to show it has created a stable country. But harmony has been hard to achieve in Xinjiang, a rugged region three times the size of Texas with deserts, mountains and the promise of huge oil and natural gas reserves. Xinjiang is also the homeland for 9 million Uighurs, a Turkic-speaking group. Many Uighurs believe the Han Chinese, who have flooded into the region in recent years, are trying to crowd them out. They often accuse the Han of prejudice and waging campaigns to restrict their religion and culture. The Han Chinese allege the Uighurs are backward and ungrateful for all the economic development and modernization the Han have brought to Xinjiang. They also complain that the Uighurs' religion - a moderate form of Sunni Islam - keeps them from blending into Chinese society, which is officially communist and largely secular. UN High Commissioner for Human Rights Navi Pillay called the violence a "major tragedy" and said all sides should "exercise great restraint so as not to spark further violence and loss of life." The authorities have been trying to control the unrest by blocking the Internet, including social networking sites such as Facebook, and limiting access to texting services on cell phones. At the same time, police have generally been allowing foreign media to cover the tensions. In a sign the government was trying to address communal grievances after the factory brawl in southern China, the official Xinhua News Agency said Tuesday that 13 people had been arrested, including three from Xinjiang. Two others were arrested for spreading rumors on the Internet that Xinjiang employees had raped two female workers, the report said, citing a local police official. Chinese officials dismiss claims that the Urumqi rioting was caused by long-simmering resentments among the Uighurs. They said the crowds were stirred up by US-exiled Uighur activist Rebiya Kadeer and her overseas followers, who used the Internet to spread rumors. "Using violence, making rumors, and distorting facts are what cowards do because they are afraid to see social stability and ethnic solidarity in Xinjiang," Foreign Ministry spokesman Qin Gang said in Beijing during a blistering verbal attack on Kadeer. She has denied the allegations. In Washington, D.C., Kadeer accused China of inciting the ethnic violence, saying peaceful Uighur demonstrators have been targeted as part of the continuing repression in the region by the Chinese government. "I'm not responsible," Kadeer, president of the Uyghur American Association said, during a rally. "The Chinese authorities instigated the violence."