A huge military build-up is being reported around China's ethnically divided Xinjiang region where clashes over the past few days claimed 35 lives.
The deadliest unrest in years in China's western region of Xinjiang was carried out by a gang engaged in "religious extremist activities", state media reported, saying the group had been busy buying weapons and raising money.
Beijing initially called last week's incident in which 35 people were killed a "terrorist attack".
Xinjiang is home to the mainly Muslim Uighur people who speak a Turkic language. Many deeply resent what they call Chinese government restrictions on their culture, language and religion. Beijing accuses extremists of separatism.
The animosity between the majority Han Chinese and the Uighurs poses a major challenge for China's Communist Party leaders. President Xi Jinping, who took office in March, has called for the unity of all ethnic groups in China.
According to reports on the government website of Xinjiang and the state news agency Xinhua, last week's attacks occurred after police arrested a member of the gang.
The next day the same gang went on a rampage in the remote township of Lukqun, about 200 km (120 miles) southeast of Xinjiang's capital of Urumqi.
The group attacked a police station, shops and a construction site. Twenty-four civilians, both Uighur and Han Chinese, and police were killed, along with 11 gang members.
"We will step up actions to crack down upon terrorist groups and extremist organisations and track the wanted," a member of the party's Politburo Standing Committee, Yu Zhengsheng, said after arriving in Urumqi, Xinhua news agency reported.
The drill came ahead of the fourth anniversary of riots in Urumqi between members of China's mostly Muslim Uighur ethnic minority and its Han majority, which left around 200 dead.
A senior member of the Chinese Communist Party has called for 24 hour patrols in the area.
Rights groups for the mostly Muslim Uighur minority deny state claims that outbreaks of unrest in the region are terrorism, instead blaming unrest on economic inequality and religious repression.