The Chinese President Hu Jintao dramatically abandoned the G8 summit in Italy yesterday to return home and deal with the worst ethnic violence to hit his country in decades.
In Urumqi, where at least 156 people have been killed, troops poured on to the streets to stamp out the last pockets of dissent. Officials said that anyone found guilty of killings during the riots would be executed.
The far-flung western city near the border with Kazakhstan was largely calm after the Uighur riots on Sunday and the bloody reprisal attacks by Han Chinese on Monday and Tuesday.
But Mr Hu felt compelled to make an embarrassingly abrupt departure from the gathering of world leaders in L'Aquila, skip a bilateral meeting with the US President Barack Obama and postpone a state visit to Portugal. "This is an unprecedented return. They must be gravely concerned because if he could have dealt with this by phone or put it in the hands of other leaders, he would have done," said Bonnie Glaser, a China expert at the Washington-based Centre for Strategic and International Studies. "It's evidence that the Chinese were taken by surprise; it reflects the misjudgement on the part of the leadership; and it suggests there are divisions within the Standing Committee of the Politburo about how best to proceed".
In the Uighur quarter of Urumqi, it seemed martial law had been imposed in all but name. Thousands of paramilitary police fanned out through the streets, some carrying rifles with bayonets, others equipped with semi-automatic weapons. It was a calculated show of force, designed to stifle any lingering thoughts of protest. Helicopters clattered overhead. Water cannons and tear gas vans were out in force. Trucks had their sirens blaring and broadcast government propaganda, telling people not to get involved in violence or carry weapons: "Strike against criminals. Stop violence. Be loyal to the Party. Follow orders."
In Han areas, there was a greater sense of normality. Paramilitary forces could be seen but in many parts security was limited to fresh-faced riot police dressed in boilersuits and sandals.
While Han Chinese took their children to the park or enjoyed a stroll in the setting sun, many Uighurs were too scared to leave home. "Doing even simple things becomes frightening," Mohammed Ali told Reuters.
Witnesses saw small groups of vigilantes on the streets and there were reports of small-scale scuffles but nothing to match the previous days when Han Chinese had rampaged through town with meat cleavers and clubs and Uighurs had attacked passers-by with bricks and knives.
Yesterday, Chinese state media played down ethnic tensions, focusing on tales of Han and Uighur people helping each other during the violence, and calling for calm in their editorials.
"History repeatedly proves that with a unified nation and ethnic solidarity, government functions well and the economy flourishes... but when ethnic harmony is destroyed it causes social turmoil and development is halted," the official People's Daily said.
City officials also tried to draw a line under the crisis. "A handful of Han attacked Uighurs and there were a handful of Uighurs who attacked Han... this handful of violent elements has been caught by the police and now the situation has been quelled," the local Communist Party chief, Li Zhi, said.
Some people were still looking for loved ones. Dong Yuanyuan was at one of the main hospitals, trying to find her husband. She had not seen him since Sunday when they were dragged off a bus en route to their honeymoon and beaten. "He must be unconscious," she told the Associated Press. "They have been searching the urgent care wards but have not found him yet."
There were also fears for the 1,434 people arrested, many of whom are reportedly students. Mr Li issued a stark warning: "To those who committed crimes with cruel means, we will execute them.
Quentin Sommerville is the BBC's China correspondent