Chinese President Hu Jintao will not attend the G8 summit in Italy because of continuing ethnic unrest in the western province of Xinjiang.
The Foreign Ministry said Mr Hu had left for China due to the ‘situation’ in Xinjiang, where 1,080 people have been injured and 1,434 arrested in unrest between Han Chinese and Muslim Uighurs since Sunday.
State Councillor Dai Bingguo will attend the G8 summit in President Hu's place, the ministry added.
China has poured troops into the city of Urumqi in a massive show of force, but fresh unrest flared as Han Chinese and Muslim Uighurs armed themselves with makeshift weapons.
The city descended into chaos at the weekend as mobs, sometimes made up of thousands of Han, entered Uighur neighbourhoods, only to be pushed back by security forces.
Thousands of riot police have assembled on main road dividing the city centre from a Uighur district, with columns of soldiers behind them.
But while the mobs have not returned and there has been no more bloodshed, many Han Chinese and some Uighurs are still carrying weapons in the city centre and outlying districts.
Expatriate Uighur leader Rebiya Kadir has claimed that police killed 400 Uighurs at the weekend.
The official death toll is 156, though authorities have not said how many were Uighur.
Ms Kadir said Uighur sources within 'East Turkestan', the separatist name for the region, had told her 400 Uighurs had died 'as a result of police shootings and beatings' in Urumqi since the violence erupted there on Sunday.
The president of the World Uighur Congress said unrest was spreading across the region and unconfirmed reports said more than 100 Uighurs had been killed in Kashgar, another major city in Xinjiang.
China has blamed Ms Kadir for instigating the violence, which she strongly denies.
