• Riot police move to break up crowds in Urumqi • Hundreds take to the streets wielding sticks and shovels

This article is more than 11 years old

This article is more than 11 years old

A new wave of violence hit the capital of the Chinese region of Xinjiang today as thousands of angry Han Chinese rampaged through Urumqi, many smashing up Uighur stores and seeking vengeance for Han deaths at the weekend.

The authorities swiftly imposed a curfew on the restive city in an attempt to quell what the government has already described as the worst riots since the foundation of the People's Republic 60 years ago. Police attempted to disperse today's mob with teargas as they headed towards a predominantly Uighur area, but many were still on the streets armed with whatever came to hand: wooden staves, iron bars, metal chains, nunchuks, shovels and axes.

Rioters smashed Uighur restaurants, threw rocks at a mosque and threatened residents of Uighur areas, although moderates in the crowd attempted to restrain them.

"They attacked us. Now it's our turn to attack them," one protester told Reuters. Another said: "We're here to demand security for ourselves. They killed children in cold blood."

"It's your time to suffer," they shouted at some of the five- and six-storey apartment blocks lining Xinfu Road.

At least 156 people have been killed and more than 1,000 injured since ethnic clashes broke out at the weekend.

Navi Pillay, the UN high commissioner for human rights, called for "great restraint" on all sides "so as not to spark further violence and loss of life". "This is a major tragedy," she said.

There is no official breakdown yet of fatalities and casualties from Sunday's violence, when an Uighur protest at mistreatment turned into full-scale ethnic clashes.

But witnesses described vicious and apparently indiscriminate attacks on Han Chinese people, although substantial numbers of Uighurs and other ethnic minorities were also injured.

Crowd members today told the Guardian that they believed Uighurs were coming back to attack them.

A respectable-looking middle-class woman carried a plank with a nail sticking out of it; a young woman in a colourful, patterned top and white diamante mules clutched a piece of metal pipe. A father held his young son in one hand and a length of wood in the other.

"We just want to defend our stuff," said one man.

Few people seemed to know where rumours of further attacks had come from, but witnesses told Reuters that earlier in the day groups of around 10 Uighur men armed with bricks and knives had attacked Han Chinese passersby and shop owners until police arrived.

"They were using everything for weapons, like bricks, sticks and cleavers," said Ma, an employee at a nearby fastfood restaurant. "Whenever the rioters saw someone on the street, they would ask 'are you a Uighur?' If they kept silent or couldn't answer in the Uighur language, they would get beaten or killed."

It was not clear if anyone died in those reported attacks.

Authorities were initially slow to react as large numbers of Han Chinese gathered on the streets around the People's Square in the centre of the city from around 2pm.

But the city's Communist party chief, Li Zhi, later took to the streets, using a bullhorn from the top of a police four-wheel drive to beg protesters to calm down and go home.

Police stopped the crowd entering an Uighur neighbourhood, but even teargas could not disperse them.

Journalists who tried to follow the crowd were bundled away from the scene "for their own safety", as protesters turned angrily on some cameramen, shoving and shouting at them.

Elsewhere in the capital, officers pleaded with gangs to go home. One told protesters holding wooden and metal bars: "Please stand away. We are a nation united."

A man replied: "Our brothers and sisters have been bloodied."

Another officer told the mob: "We need to protect the law. Please retreat. Please trust us."

Banks closed their doors and staff crouched inside, some holding staves, while hotel staff taped up windows.

Earlier in the day Chinese armed police and Uighurs clashed as residents erupted into protests during an official media tour of the riot zone, in the face of hundreds of officers.

Women in the marketplace burst into wailing and chanting as foreign reporters arrived, complaining that police had taken away Uighur men.

Authorities have arrested 1,434 people in connection with Sunday's unrest.