A gunman has wounded three people - two of them critically - at a college in the US state of Arizona.

The incident occurred at about 1600 (2100 GMT) at the South Mountain Community College in the state capital, Phoenix, police say.

They said that the gunman had been arrested, but gave no details.

There have been a number of school and college shootings in the US in recent years. In April 2007 a student killed 32 people and himself at Virginia Tech.

In Thursday's incident in Pheonix, a 25-year-old man and a 22-year-old woman were critically wounded, while a 17-year-old boy is in stable condition

"There was a scuffle in the hallway," one witness told CBS TV News.

"The guy started randomly shooting. I ducked down."