Authorities in the troubled western region of Xinjiang are maintaining a tight grip on the regional capital Urumqi, even after the closure of an international trade fair, residents said Tuesday.
There is still a strong volunteer security force on the streets of the city, said Urumqi-based rights activist Zhang Haitao, who has been under police surveillance at his home during the China-Euro Expo, which ended Monday.
"There are still a lot of [volunteers] and a lot of patrol cars," he said. "There are red armband [security volunteers] at every public transport stop."
The additional security could remain until after the Oct. 1 National Day holiday week, said Zhang, who suspects that the authorities jammed his home lock to prevent him from going out.
The lock's "all blocked now, and looks like it's got toothpicks in it."
Beijing had ramped up security before and during for the five-day China-Eurasia Expo trade fair in Urumqi, where deadly ethnic riots killed at least 197 people two years ago.
The added security measures followed a fresh clampdown on Uyghur Muslims in the wake of separate attacks in the Silk Road cities of Kashgar and Hotan that killed more than 30 people in July.
The period marked the bloodiest violence in a year in Xinjiang, where many Muslim ethnic Uyghurs chafe under Chinese rule.
An Urumqi resident surnamed He said he had seen police on training exercises.
"There are riot police doing training exercises in the northern suburbs of Urumqi," He said. "I have just been over there to take a look."
"They have them every day," He said, adding that the traffic controls in place during the Expo have mostly disappeared.
"There are checks being carried out on roads coming in from the northern suburbs," said He, "but I haven't seen them anywhere else."
"[The checkpoints] are still there, though. They will stay until after Oct. 1."
According to Dilxat Raxit, spokesman for the Munich-based World Uyghur Congress, most of the security measures target the Uyghurs.
"All the investigations and armed police control points in strategic locations are aimed at Uyghurs," Raxit said.
He said the 10th anniversary of the Sept. 11 terrorist attacks on the United States is adding to the tension in the region, where the Chinese authorities have blamed religious extremists and separatist groups trained in Pakistan for a string of violent attacks in recent months.
"The authorities are continuing their controls and oppression in the region, even though the Expo is now over," Raxit said.
"They haven't stopped their investigations and checks on Uyghurs," he said. "And the 10th anniversary of 9/11 is nearly here."
"Also, there is China's National Day and a slew of other sensitive dates, which has made Uyghurs the target of 'strike hard' campaigns by the Chinese goverment and various controls and investigations," Raxit said.
China has said it foiled "terror" plots by extremists during a visit by Pakistani President Asif Ali Zardari, who attended the opening of the Expo.
Beijing has billed the trade fair as an opportunity to develop trade and economic cooperation between Central Asian economies.
The convention center in suburban Urumqi was guarded by police carrying rifles, while S.W.A.T. units were deployed to handle the security check at the entrance, official media reported.
Kyrgyz President Roza Otunbayeva, Azerbaijan's vice premier Abid Sharifov, and Kazakhstan's deputy prime minister Aset Isekeshev also attended the fair's opening.
Official media say Beijing wants to turn Urumqi into an important exchange platform for leaders and businesses in China and its western and southern neighbors, including Russia, Kazakhstan, and Pakistan.
But some experts believe Beijing's rapid development of Xinjiang, which they say has created more opportunities for Han Chinese than for the local Uyghur population, is leading to additional ethnic tension in the region.
Reported by Qiao Long for RFA's Mandarin service. Translated and written in English by Luisetta Mudie.