URUMQI, China – Yang Bin and Chen Li stand out in their neighborhood in the capital of China's Muslim northwest. The couple from the country's Han ethnic majority live surrounded by minority Uighurs, but have little to do with their neighbors.
"We don't speak their language, so we don't interact with them at all," Yang, a laborer, said of the Turkish-speaking Muslims. His wife added: "They are basically foreigners, and they behave like foreigners."
State media say ethnic Chinese and minorities mix easily in Urumqi, capital of the Xinjiang region. But interviews with more than two dozen residents following Thursday's bombing at a vegetable market in the city that killed at least 43 people suggest a harsher reality in which the two groups regard each other across a tense gulf of misunderstanding and suspicion.
Relations have deteriorated since rioting in 2009 left nearly 200 people dead. Both groups are moving out of ethnically mixed neighborhoods, making an already divided city of 3 million people even more segregated.
The tensions raise questions about how Beijing can defuse mounting unrest that Uighur activists say is due to frustration over an influx of Han Chinese and discriminatory policies such as a ban on taking children to mosques.
The region is part of a campaign launched in the 1990s and dubbed "Develop the West" that aims to raise incomes in Xinjiang, Tibet and other minority areas and bind them to China's Han east with railways and other infrastructure. Uighurs, however, say the benefits have gone to Han migrants who have been encouraged to flood into the area.
"There is greater discontent now and recognition that the Uighur character of the region is being irretrievably lost," Ahmed A.S. Hashim, a terrorism expert at Singapore's Nanyang Technical University, said in an email.
"Chinese promises to develop (the economy) and provide jobs don't seem to have panned out," Hashim said.
In Thursday's attack, men in two off-road vehicles rammed through crowds at the popular street market in central Urumqi and set off explosives.
Authorities said four suspects were killed in the attack and that a fifth was captured Thursday night. Based on names released by the government, the suspects appeared to be Uighurs.
On Sunday, the government called on anyone involved in terror activities in Xinjiang to turn themselves in. They were promised leniency, especially those who implicate other militants.
The government blames the unrest on separatists with ties to Islamic terror groups abroad. Foreign experts say they see no evidence of that. Attacks so far have been relatively crude, using knives and bombs.
The evolution of the neighborhood where the bombing occurred reflects the separation of Urumqi into Han and Muslim sections.
Following the 2009 riots, Urumqi's Uighur residents moved to the city's heavily Muslim south, leaving the area dominated by Han Chinese, according to a Western resident who operates a business nearby. The Westerner asked not to be identified by name or nationality due to the political sensitivity of the ethnic divide.
"Urumqi has become a more segregated city, particularly since the riots in 2009," said David Brophy, a historian at the University of Sydney who lived in the city a decade ago.
A Han woman, who like many interviewed for this article refused to give her name, said her friends call ethnic Chinese neighborhoods "the liberated zone" and those of Uighurs "the enemy's zone."
Authorities are unlikely to allow an independent study of the demographic shift due to the political sensitivity of ethnic tensions, Brophy said.
A bomb attack last month at an Urumqi train station that killed three people, including two of the attackers, might have been targeted as a symbol of Han migration into the region, he said.
Several residents in Urumqi also believed Thursday's attack was ethnically motivated because of the predominance of Han residents.
Unlike some other ethnic minorities, Uighurs have retained a distinctly separate culture, speaking a Turkic language that has no relation to Chinese and following Muslim traditions like those of Central Asia.
The ruling Communist Party says the region has been part of China for more than 1,000 years, but its people have a long history of rebellion against foreign rule.
Yang Hanjiang, a Han Chinese taxi driver, deplored what he said was a lack of knowledge by Han people about the Uighurs.
"The Chinese do not really interact with the Uighurs," Yang said. He went on to express a sentiment that reflects Han unease: "In every Uighur's heart and mind, independence is their dream."
Despite an official policy to promote ethnic unity, Han increasingly view Uighurs as separatists and Muslim terrorists, according to Hashim, the terrorism expert.
It is common for both Uighurs and Han to "express quite hostile or prejudiced views," said Brophy, the Australian historian.
"The violence is an indication that people are willing to take more drastic measures to express their opposition, and those attacks in turn increase Han hostility to Uighurs," Brophy said. "We're in a bit of a vicious circle now."
The latest attacks have left Urumqi's ethnic Chinese on edge about their Muslim neighbors.
At a convenience store on a street near the vegetable market, the operator spoke of heightened alert whenever a Uighur steps in. "If it is a Uighur man, we follow him in the store in case he could place something here, like an explosive," Jiang Lulu said. "We have been told by the government to take extra precautions here."
Longtime Han residents say their relationship with Uighur friends is changing.
"We are speaking less with each other, and they don't trust us," said a Xinjiang-born Han resident, who asked not to be identified by name. "Now, there is something between us."
A Han taxi driver grumbled when a visitor asked to be taken to the Grand Bazaar in a Uighur neighborhood and urged her to get out quickly when they arrived. A Han vendor in the bazaar explained that drivers are worried they might pick up potential attackers there. Drivers said no male passenger is allowed to sit in a taxi's front seat after 10 p.m. but must sit in the back, separated by metal bars.
A Uighur woman complained that a grade school Han classmate called her daughter "livestock" repeatedly in class without being stopped by their Han teacher.
"We are living on our own land," said the woman, who refused to give her name, "but we feel like we are foreigners."
Watt reported from Beijing.