The condition of a Chinese woman tourist critically injured in last week's tour bus crash in Arizona has improved, a spokesman of the hospital where she is receiving treatment said Friday.

The condition of the 35-year-old woman from Shanghai has been upgraded from critical to serious, while that of another woman was still critical, said Rick Plummer, spokesman of the University Medical Center in Las Vegas.

Two other crash victims, a 61-year-old man and a 41-year-old woman were still receiving treatment at the medical center, and both were in good condition, Plummer said.

He said the condition of the 48-year-old local bus driver was stable.