URUMQI, China– Han Chinese armed with iron bars and machetes spilled down side streets and into the stairwell of an apartment building on Tuesday, looking for Muslim Uighur targets two days after bloody ethnic clashes killed 156 and wounded more than 1,000.

Chinese riot police used tear gas to try to break up protests in the capital of the Muslim region of Xinjiang and will enforce an overnight curfew to try to quell the violence in which many people were wounded. There were no immediate reports of deaths.

Hundreds of protesters from China's predominant Han ethnic group, many clutching meat cleavers, metal pipes and wooden clubs, smashed shops owned by Uighurs, a Turkic largely Islamic people who share linguistic and cultural bonds with Central Asia.

Some Han Chinese shouted attack Uighurs as both sides hurled rocks at each other. Some entered the stairwell of one apartment building and tried to smash open the door of another as residents rained down rocks from the roof. Police eventually dispersed the crowd.

Police used tear gas to try to disperse the crowd, but for a while it only emboldened the demonstrators, caught between two sets of anti-riot police 600 meters (yards) apart.

Some used water to wash the gas out of their eyes as they pressed toward police at the mainly Uighur end of the street.

They attacked us. Now it's our turn to attack them, a man in the crowd told Reuters. He refused to give his name.

Along with Tibet, Xinjiang is one of the most politically sensitive regions in China and in both places the government has sought to maintain its grip by controlling religious and cultural life while promising economic growth and prosperity.

The violence, which has showed signs of spreading in the volatile region, appeared to have little impact on China's financial markets. Stocks slipped on technical factors while the yuan was trading higher against the dollar.

Xinjiang has long been a hotbed of ethnic tensions, fostered by a yawning economic gap between Uighurs and Han Chinese, government controls on religion and culture and an influx of Han Chinese migrants who now are the majority in most key cities.

Beijing has poured cash into exploiting Xinjiang's rich oil and gas deposits and consolidating its hold on a strategically vital frontierland that borders Pakistan, Afghanistan and Central Asia, but Uighurs, who launched a series of attacks to coincide with the buildup to last year's Beijing Olympics, say migrant Han are the main beneficiaries.

TIME TO FIGHT BACK

Part of the crowd briefly surged forward singing the Chinese national anthem before police drove them back with tear gas.

Anti-riot police armed with clubs and shields pushed protesters away from a Uighur neighborhood but hundreds managed to break through police lines.

Many of the Uighur protesters were women, wailing and waving the identity cards of husbands, brothers or sons they say were arbitrarily seized in a sweeping reaction to Sunday's rioting in the city of Urumqi.

My husband was taken away yesterday by police. They didn't say why. They just took him away, a woman who identified herself as Maliya told Reuters.

Abdul Ali, a Uighur man in his 20s who had taken off his shirt, held up his clenched fist. They've been arresting us for no reason, and it's time for us to fight back, he said.

Ali said three of his brothers and a sister were among 1,434 suspects taken into custody. Of the 156 killed, 27 were women.

Human rights groups have warned that a harsh crackdown on Uighurs in the wake of Sunday's violence could merely exacerbate the grievances that fueled ethnic tensions.

Navi Pillay, U.N. High Commissioner for Human Rights, said demonstrators had the right to protest peacefully and that those arrested should be treated in line with international law.

I urge Uighur and Han civic leaders, and the Chinese authorities at all levels, to exercise great restraint so as not to spark further violence and loss of life, Pillay said in a statement. This is a major tragedy.

Urumqi Communist Party boss Li Zhi defended the crackdown and confirmed the government had cut internet services to parts of the city to prevent violence spreading.

It should be said that they were all violent elements who wielded clubs and smashed, looted, burned and even murdered at the scene, he told a news conference.

UNREST SPREADING?

Some Xinjiang newspapers carried graphic pictures of the violence, including corpses, at least one of which showed a woman whose throat had been slashed.

Despite heightened security, some unrest appeared to be spreading in the volatile region, where long-standing ethnic tensions periodically erupt into bloodshed.

Police dispersed around 200 people at the Id Kah mosque in Kashgar in southern Xinjiang on Monday evening, Xinhua said. The report did not say if police used force but said checkpoints had been set up at crossroads between Kashgar airport and downtown.

Almost half of Xinjiang's 20 million people are Uighurs, while the population of Urumqi, which lies around 3,300 km (2,000 miles) west of Beijing, is mostly Han.

Chinese officials have already blamed the unrest on separatist groups abroad which it says want to create an independent homeland for Uighurs.

The Chinese embassies in Germany and the Netherlands were attacked by exiled pro-Uighur activists who smashed windows, a Foreign Ministry spokesman said on Tuesday. China condemned the attacks.

Wu'er Kaixi, a Uighur and one of the best known dissidents from the Tiananmen Square crackdown in Beijing 20 years ago, said there had been no improvement in China's human rights record.

For a long time, Uighurs have been discriminated against and suppressed in China, he told a news conference in Taiwan. So much so that we're almost colonized by China.

(Additional reporting by Emma Graham-Harrison, Yu Le and Benjamin Kang Lim in Beijing; Paul Eckert in Washington; Ben Blanchard in Shanghai; and Christine Lu and Ben Tai in Taipei; Writing by Nick Macfie; Editing by Jeremy Laurence)