Last update 9:22 p.m. ET.
China's state news agency says police have arrested 1,434 suspects in connection with the worst ethnic violence in decades in the western Xinjiang region, which killed at least 156 people.
Xinhua News Agency did not immediately give any further details Tuesday.
In Urumqui, where the riots took place Sunday, hundreds of paramilitary police chanted "Strike down the criminals" and wielded shields, rifles and clubs as they took control of the streets Monday in the capital of western China's Muslim region
Mobile phone service and the social networking site Twitter have been blocked, and Internet links have been cut or slowed down.
The unrest began after 1,000 to 3,000 protesters - mostly students - gathered downtown at the People's Square and protested the June 25 deaths of Uighur factory workers killed in a riot in southern China. Xinhua said two died; others say the real figure was higher.
The 156 deaths, reported by state media did not bode well for China's efforts to mollify long-simmering ethnic tensions between the minority Uighur people and the ethnic Han Chinese in Xinjiang - a sprawling region three times the size of Texas that shares borders with Pakistan, Afghanistan and other Central Asian countries.
As darkness fell, security forces became especially tense and ordered residents off the roads near the main gate at Xinjiang University - the scene of some of the worst clashes Sunday.
As people watched from an apartment building across from the school, riot police in green camouflage uniforms and helmets pointed long sticks at the gawkers and barked, "Close those windows!"
The government often says the Uighurs should be grateful for the roads, railways, schools, hospitals and oil fields it has been building in Xinjiang, a region known for scorching deserts and snowy mountain ranges.
Many Uighurs (pronounced WEE-gers) haven't been wooed by the rapid economic development. Some want independence, while others feel they're being marginalized in their homeland. The Han - China's ethnic majority - have been flooding into Xinjiang as the region becomes more developed.
A similar situation exists in Tibet, where a violent protest last year left many Tibetan communities living under clamped-down security ever since.
"The Han Chinese say we all belong to the same country. We're all part of one big family," said Memet, a restaurant worker who like other Uighurs declined to give his full name because he feared the police. "But the Han always treat us separately."
A Han Chinese shopkeeper, who only gave his surname Wang because the ethnic issue is so sensitive, disagreed. "Those who cause such trouble are criminals," he said. "They're never happy with what they have."
Sunday's violence was notable because it happened in Xinjiang's capital, Urumqi, which has been relatively peaceful and hasn't been a hotbed of religious or political agitation. In other restive Xinjiang cities, red propaganda banners are filled with slogans encouraging ethnic harmony. But most of the banners in Urumqi touted anti-drug and fire prevention campaigns.
The population of 2.3 million is also overwhelmingly Han Chinese in the city, a mixture of drab concrete apartment blocks and gleaming new office towers.
"There were several hundred people who marched past my shop. I didn't feel threatened. They were peaceful and chanting, 'Uighurs will be victorious,"' said a convenience store clerk who only gave her surname, Zhang, of the People's Square protest.
Poor quality amateur video purportedly showed a surging crowd of hundreds running through traffic. It was shot from an upper floor of a building and was posted on YouTube.
The police eventually showed up in force, and it's unclear who struck first.
Rioters began flipping over barricades, smashing shop windows and burning cars, according to media and witness accounts. Glass still littered the sidewalks and streets that were eerily quiet Monday because most shops and office buildings were closed. A white car being towed away was splattered with blood, and there was a large red stain on the stone steps of a hotel in the biggest Uighur district.
State television video showed protesters attacking and kicking people on the ground, and the government said many Han Chinese were injured by rampaging Uighurs.
In the video, people who appeared to be Han Chinese sat dazed with blood pouring down their faces.
There was little immediate explanation for how so many people died
There were no independent figures on the ethnic breakdown of the casualties, but many were believed to be Uighurs.
Wu Nong, director of the news office of the Xinjiang provincial government, said 828 people were wounded, more than 260 vehicles were attacked or set on fire, and 203 shops were damaged.
Memet, the 36-year-old restaurant worker, said he saw People's Armed Police attack Uighur students outside Xinjiang University.
"First they fired tear gas at the students. Then they started beating them and shooting them with bullets. Big trucks arrived, and students were rounded up and arrested," he said.
Chinese officials singled out the leader of the U.S.-based Uyghur American Association - Rebiya Kadeer, a former prominent Xinjiang businesswoman now living in Washington - for inciting the violence.
"Rebiya had phone conversations with people in China on July 5 in order to incite, and Web sites ... were used to orchestrate the incitement and spread propaganda," Xinjiang Gov. Nur Bekri said Monday on television.
Xinjiang's top Communist Party official, Wang Lequan, said: "We must tear away Rebiya's mask and let the world see her true nature."
Kadeer said Monday that she had learned through Web sites of the planned protests and called her brother to urge him and other family members to stay away.
"The Chinese government always blames me and the World Uyghur Congress for problems over there," Kadeer said in Washington, D.C. "Any Uighur who dares to express the slightest protest, however peaceful, is dealt with by brutal force."
While she blamed the government for the recent violence, she also condemned "the violent actions of some of the Uighur demonstrators" and said her organization only supports peaceful protests.
"China's violent crackdown in Xinjiang is based, in part, on China's allegation that the some of the Uighurs are associated with the East Turkestan Islamic Movement, which was designated by both the U.N. and the U.S. as an al Qaeda-affiliated terrorist organization," said CBS News Foreign Affairs Analyst Pamela Falk, from Beijing. "That is why there was so much sensitivity about what to do with the 17 Uighur detainees who had been held in Guantanamo."
Falk reports that the region has been on the radar of the U.S. and the U.N. for more than a decade, "because of the mix of terrorist organizations stoking violence, on the one hand, and the religious freedom issues of the Chinese Muslim community, on the other."
"And although there has been violence in the past in the far western region of China, the scope of the fighting is larger and unexpected at a time when President Hu Jintao is out of the country, promoting the strength of the Chinese economy," Falk added.
Witnesses reported a new, smaller protest Monday in a second city, Kashgar, home to the Id Kah Mosque, the biggest in Xinjiang.
In Urumqi, most Han Chinese stayed indoors and many Han taxi drivers refused to drive into Uighur neighborhoods, where the air was filled with the scent of lamb kebabs cooking over long grills. Although more Uighurs were on the streets, they said they were worried about being picked up by police, who were still arresting protest suspects.
"I went outside last night and saw all the chaos and went back inside," said a Uighur office worker who only gave her given name, Guli. "I heard a lot of gunfire. Then today, the police were questioning people and visiting homes.
"My biggest fear is that I'll say the wrong thing to the police, and then it will be all over for me," Guli said, making a throat-slashing gesture with her hand.
Hundreds of paramilitary police sealed off a wide boulevard in front of the university, where witnesses said scores of protesters were killed. They chanted, "Strike down criminals, uphold the law." In the evening, they dispersed crowds of Uighurs by yelling, "For your own safety, go home."
As a middle-aged Uighur woman shuffled away, she said sarcastically under her breath, "It's always safety first here."
The paramilitary police then began marching through the empty streets in Uighur neighborhoods in tight columns with an armored troop carrier following them. The security forces were all Han Chinese, and some Uighurs rolled their eyes or made funny faces after the police walked by chanting, "Let's protect Xinjiang!"
© 2009 CBS Interactive Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.