(Adds Xinjiang parliament delegate comments, quotes from expert)
By Michael Martina
BEIJING, March 6 (Reuters) - A deadly knife attack at a Chinese train station last week should not be linked to ethnicity, a senior government official said, days after authorities blamed the incident on separatists from the country's troubled far western region of Xinjiang.
China says militants from Xinjiang, home to a large Muslim Uighur minority, launched a terrorist attack in the southwestern city of Kunming, killing at least 29 people and injuring about 140.
It was one of the worst bouts of violence to spill out of the restive region, where more than 100 people, including several policemen, have been killed in unrest since last April.
Fear and resentment between majority Han Chinese and Uighurs had spread since the attack, said Zhu Weiqun, the chairman of the ethnic and religious affairs panel of the top advisory body to parliament, which meets this week in Beijing.
"Such sentiments - although not widespread - deserve our attention," Zhu told the official China Daily, adding that the "overwhelming majority" of the migrant Uighurs from Xinjiang were "good people".
"Most Uighurs are with us in the fight against separatism and violent terrorism," he said in an interview in the English-language newspaper published on Thursday. "They sincerely support the central government.
"...We should not relate such cases to an ethnic issue in a casual way."
The comments highlight Beijing's concern over the growing frictions between Uighurs and Han Chinese and the potential for further unrest.
After the Kunming attack, many residents voiced ethnic concerns to Reuters reporters and some businesses and hotels displayed signs turning away Uighurs.
Online accounts have described growing discrimination against Uighurs, ranging from their evictions from apartments to refusals by taxi drivers to give them rides.
Beijing has not explicitly accused Uighurs of carrying out the Kunming attack, but by calling the perpetrators Xinjiang extremists the implication is clear.
State media have reported that a female suspect was injured and captured in the attack in Kunming, the capital of Yunnan province, which is hundreds of miles southeast of Xinjiang, and that three suspects, including another woman, had been caught. Four were shot dead.
Chinese authorities should stop using the attack to carry out "extreme propaganda" and "incite racism", Dilxat Raxit, a spokesman for key exile group the World Uyghur Congress, said in an emailed statement late on Wednesday.
Many Uighurs say they are infuriated by Chinese curbs on their culture and religion, though the government says they are given wide freedoms.
China bristles at suggestions from exiles and rights groups that the unrest is driven more by unhappiness at government policies than by any serious threat from extremist groups who want to establish an independent state called East Turkestan.
Authorities say many have links with foreign groups, although rights groups and some foreign experts say there is little evidence to support this.
"Foreign forces committing crimes have always been behind separatist activities,"," Xinjiang's governor, Nur Bekri, told reporters at a briefing on the sidelines of parliament on Thursday.
"We will remain on high alert for this," he said.
China stepped up security in Xinjiang after a vehicle ploughed into tourists on the edge of Tiananmen Square in October, killing the three people in the car and two bystanders. China labelled it a suicide attack by militants from Xinjiang.
After three years in which China's domestic security budget exceeded its fast-growing military budget, this year the government did not publicise the overall figure despite an increased focus on stability at home.
Experts say that is an indication of how sensitive the government is to perceptions of its handle on security, especially after it failed to predict or prevent the two major incidents in Kunming and on Tiananmen Square.
Philip Potter, an assistant professor at the University of Michigan who researches international terrorism, said the security crackdown in Xinjiang could be pushing attacks towards "softer" targets in other parts of China.
"This is a structural problem that I don't think they can spend their way out of," Potter said, adding that the security presence in Xinjiang was nearing its limits.
"This means that there are two options - tolerate the existing status quo with the caveat that the attacks may get worse as militants get more sophisticated, or start thinking about how to address the underlying grievances of the Uighurs." (Additional reporting by John Ruwitch in SHANGHAI; Editing by Nick Macfie)