At least 1,000 military and police personnel staged a show of force in Urumqi, the capital of Xinjiang, as state media announced a one-year crackdown on terrorism in the region after an attack on Thursday in which 31 people were killed.
The show of force was made outside the city government offices in Nanhu Plaza. Zhang Chunxian, Xinjiang Communist Party secretary, urged security personal to carry out the "spirit" of President Xi Jinping's anti-terrorism campaign.
"The campaign will make full use of political and legal forces, army and armed police in Xinjiang," Xinhua said, adding that the aim was to "focus on terrorists and religious extremist groups, gun and explosive manufacturing dens and terrorist training camps".
"Terrorists and extremists will be hunted down and punished. The government will prevent terrorism and extremism from spreading to other regions."
The drive, approved by the central government and a national-level group leading anti-terrorism activity, would last until June next year with Xinjiang as the "major battleground".
Washington condemned Thursday's "horrific terrorist attack" and UN Secretary General Ban Ki-moon said there was no justification killing civilians.
Assailants in two vehicles ploughed into shoppers and traders and threw explosives at a street market. One of the vehicles exploded and more than 90 people were injured.
Global Times reported that five people carried out the bombing, but did not identify the source of the information. The newspaper said authorities "are investigating whether there were other accomplices".
The paper cited witnesses as saying four vehicles were involved, and a witness said there were more than two, but authorities issued no confirmation.
No group has claimed responsibility for the attack.
The incident was the second suicide attack in the capital in just over three weeks. A bomb and knife attack at an Urumqi train station in late April killed one bystander and wounded 79.
The government blames Islamists and separatists for the worsening violence in the western region. Xi pledged following the attack to "severely punish violent terrorists", and "crack down on them with a heavy fist".
"Judging from the many terrorist attacks that have taken place and the relevant perpetrators, they have received support from terrorist groups outside China's borders as well as religious extremist propaganda spread via the internet," Foreign Ministry spokesman Hong Lei said at a daily news briefing.
Police yesterday erected a knee-high barrier at the site of the attack, but only one trader set up his stall on the street itself.
People who took photos of patrolling paramilitary police were told to delete them. Vehicles were banned from parking within 100 metres of schools. Parents were asked to walk to collect their children and not stay in the area.
White House spokesman Jay Carney said the attack was despicable and that the US resolutely opposed all forms of terrorism.
Agence France-Presse, Reuters, Associated Press