The lawyer said that before the dispute, Zhai Tiantian expressed dissatisfaction with the institute in a TV interview in which he said he wanted to sue the school for racial discrimination.

"This is probably the real reason why the school is dealing with him this way," Hai said.

Luo Gang, the overseas Chinese affairs consul with the Chinese Consulate-General in New York, said he has handled similar cases in which Chinese students had verbal clashes with others. "Chinese and American cultures are different, so what the Chinese regard as acceptable remarks may be deemed by Americans as threats. This is an unfortunate incident. We don't want to see that. The case is in the judicial phase and we can only hope the lawyers will be able to help him."

One of Zhai Tiantian's middle school classmates, surnamed Liu, called Xi'an-based Huashang Daily from Canada on Sunday expressing his concern, saying that he will never believe that Zhai Tiantian was a terrorist.

"I have known him since middle school and he was one of the best students in the school," Liu said.

Zhang Xingfan, vice-president of Shaanxi Chamber of Commerce in the US, made a phone call to Zhai Taishan on Sunday after learning the news, saying he would be happy to provide assistance to the family.

"We were shocked by the news and will pay attention to the progress of the case. As fellow Shaanxi people, we will offer any possible help to the student," Zhang said.