Sunday's deadly riot in China shocked the world as blood tainted Urumqi, with at least 156 lives lost and more than 800 others injured, barely 16 months after the nightmarish Lhasa.

Calm had settled over Urumqi, capital of western Xinjiang region, after 20,000 police, troops and firefighters reclaimed the streets from rioters who burned and smashed vehicles and shops, and clashed with security forces over Sunday night, according to Xinhua.

The police had dispersed more than 200 rioters who tried to gather at the Id Kah Mosque, the largest mosque in China, at about 6 p.m. Monday.

Officials said more than 700 suspects had been detained by Monday evening.

Urumqi, however, was still in horror as more intrigues were detected, the regional police authorities said Monday night.

Police said they got clues that some people were trying to organize more unrests in Kashi City, Yili Kazak Prefecture and Aksu City.

It was a crime of violence that was premeditated and organized, said Nur Bekri, chairman of the Xinjiang regional government, in a televised speech Monday morning.

He said three forces of terrorism, separatism and extremism made use of a fight between Uygur and Han ethnic workers in a toy factory in southern Guangdong Province on June 26, in which two Uygur workers died, to create chaos.

Admissions at the People's Hospitals, one of the biggest in Urumqi, also suggested Han Chinese were targeted.

Xinhua said the hospital received 291 people of whom 17 died later. Among them 233 were Han Chinese, 39 were Uighurs, while the rest were from other ethnic minorities.

A middle-aged man surnamed Hao said it was only an excuse of the rioters, as he witnessed the insane rioters.

At the beginning, they only beat young men of Han ethnic group, but later, they began to attack people in the streets indiscriminately, regardless of men or women, young or old, Han or Uygur, Hao said.

They can find another excuse if they really want to create disharmony among different ethnic groups and destabilize the society, he said.

Most of the shops in the Kashi were closed amid the current tension, and few people and cars were seen in the streets of Urumqi, a city of 3.5 million people.

I didn't dare go outdoors today, although it is Monday and I should go to work, said a woman surnamed Ma who works for a bank. The bank manager later notified me that I can stay at home because almost no one went to the bank.

The police had set checkpoints at crossroads from the Kashi airport to the downtown areas.

Rioters burned 261 motor vehicles, including 190 buses, at least 10 taxis and two police cars, said Yaohua Liu, the region's police chief. And the number of people killed may further over time.

Police in northwest China's Xinjiang region said Monday they have evidence that the separatist World Uyghur Congress led by Rebiya Kadeer masterminded the Sunday riot.

An unidentified spokesman of the Xinjiang regional department of public security said some people used a number of telephones outside the country to direct mobs in Xinjiang to stage the violence.

Police have obtained recordings of calls between overseas Eastern Turkestan groups and their accomplices in the country, the officer said.

In the recorded calls, Rebiya Kadeer said, Something will happen in Urumqi. She also called her younger brother in Urumqi, saying, We know a lot of things have happened, referring to the June 26 brawl involving workers from Xinjiang in a toy factory in Guangdong Province.

The spokesman said some people started posting calls on Internet forums for demonstrations in Urumqi Saturday evening, in support of protests to be held by overseas separatists.

Given its unique location and demography, the northwestern Chinese region has been a target of separatist and terrorist actions, particularly in the past two years.

Now the three forces of terrorism, separatism and extremism are at work again. Government investigations indicate that Sunday's unrest was controlled and instigated from abroad.

In response to the riot in Urumqi, Turkey hopes the persons who are responsible for these incidents will be found out as soon as possible and brought to justice, the Foreign Ministry said on Monday.

The United States urged all in Xinjiang to exercise restraint.

We are deeply concerned over reports of many deaths and injuries from violence in Urumqi in western China, said White House spokesman Robert Gibbs. Reports so far are unclear about the circumstance surrounding the deaths and injuries, so it would be premature to comment or speculate further.