Below is an article published on Radio Free Asia:

Authorities in China's troubled northwestern region of Xinjiang have boosted security patrols and military-style barricades across the capital, Urumqi, as police stepped up security checks on ethnic minority Muslim Uyghurs, residents and activists said.
Photos taken by residents and seen by RFA showed row upon row of patrolling security personnel on the boulevards and alleyways of the city, as well as in the farmers' markets.
A banner hung on the wall of a residential compound reads: "Fight the good fight for a secure 18th Party Congress." The congress will convene on Nov. 8 [2012] for a once-in-a-decade leadership transition.

According to one Urumqi resident surnamed Zhang, many alleyways and lanes had been blocked off with metal barriers.
"[Near my home] there's a mobile phone store which is always open, except now, only one of the doors is open, and there are two people guarding the door," he said.
"One of them has a handheld [body] scanner, and another is holding a police truncheon, and they're only letting one person past at a time."

Police had descended on the most lively districts of Xinjiang's regional capital, Urumqi, forcing stallholders, street musicians and other small businesses to move along, as part of a region-wide security drive to ensure social stability during the congress, Zhang said.

"They are checking every corner, every day," he said. "They are looking for so-called 'instability and insecurities'."
"Some of the alleyways have been blocked off entirely, while others have barricades or riot police in them."
A second Urumqi resident said security checks had been stepped up across all public places.
"Recently there have been tighter checks at the airport, as well as security guards posted in the supermarkets; even the small supermarkets which never had security guards in them in the past," the resident said.
"There are a large number of police patrol cars around at night, and they are stopping cars and checking them for all sorts of things, including drinking, license and tax violations," he said.
"There are no security scanners [at the gate of the Grand Bazaar], but they are checking people's bags," the resident said.

Dilxat Raxit, spokesman for the Munich-based World Uyghur Congress, said that police were currently targeting Uyghur households for raids across the whole of Xinjiang.
"They are carrying out raids in the north and in the south, and at all the border crossings," he said. "All [people and vehicles] entering Urumqi must submit to a detailed inspection."
"These measures strictly prohibit Uyghurs, and anyone who doesn't have their household registration in Urumqi," Raxit said. He said the authorities are targeting mostly Uyghur households for raids, nighttime and dawn raids, on a daily basis."There are no formalities needed for these raids," he said. "If anyone refuses to cooperate, they can be immediately detained, and if they try to fight back, they can be shot dead on the spot."
Raxit said that any Uyghurs linked to the demonstrations and subsequent ethnic clashes of 2009 in the city were particular targets of the "stability" drive.

"Anyone whose relatives died in the July 7 [violence], as well as anyone who is very pious, is under surveillance," he said.
Outside of Urumqi, similar measures were being employed in other regions of Xinjiang, Raxit said.
He said one in three government officials was on call for the entire period from Nov. 7-17 [2012].
"Districts where the Uyghurs live are on level 1 alert," he added.

Zhang said the police were in full riot gear. "Every police vehicle is full of officers," he said. "There are also volunteer soldiers in camouflage"

"They are organized into patrols of more than 12 people."