URUMQI, China, September 4, 2009 (AFP) - Jiang Ye was waiting for a friend at the train station in China's northwestern city of Urumqi when she felt a sharp stabbing pain in her left arm.

Jiang, 36, is one of more than 450 people who authorities say have been attacked in the restive capital of Xinjiang region -- the scene of deadly unrest in July pitting Han Chinese against Muslim Uighurs -- in recent weeks.

The mysterious syringe attacks sparked mass protests here on Thursday, with tens of thousands of people, most of them Han Chinese, filling the streets and demanding that the government do more to ensure public safety.

Jiang, who spoke to AFP on Friday as she left the infectious diseases department of the Xinjiang People's Hospital, said she was not afraid to come out in public after the incident, but remains concerned about her health.

"It happened the day before yesterday at the train station. I was picking someone up at the train and he was coming out with a crowd of other people when suddenly I felt this sharp stabbing pain in my arm," said Jiang, who is Han.

"I didn't see who did it. It was raining really hard and the sky was dark, but I do recall that there were some Uighurs right near me at that point."

She rolled up the left sleeve of her blouse to reveal a deep bruise the size of a coin with a pinprick hole at the center.

"I'm very worried now -- the hospital says there should be no problem, but they also said that with some diseases you won't know for six months or a year whether you have it."

Her husband, 41-year-old He Zeyong, said he joined Thursday's protests in Urumqi "out of anger" over what happened to his wife.

"As soon as I heard (about the attack), I panicked because I could not go to her because of the heavy traffic and the rain. It took me three hours to reach her. I thought I was going to die of fright."

"The government is actively taking measures now to ensure security so we are confident.... We just want things to be peaceful and safe here," said He, who runs a small grocery store with his wife.

Tens of thousands of people demonstrated in Urumqi on Thursday in anger over the mysterious syringe attacks, which have revived ethnic tensions here. State media reports have said that 476 people have been treated after being stabbed.

No one had been infected or poisoned in the assaults, Xinhua news agency reported, and it remained unclear what the syringes contained, if anything.

A female official in the hospital said: "I'm not clear about the overall figure of cases, but I know there were many."