LOS ANGELES - Three people were wounded after a student opened fire at a school in New Mexico, authorities said Tuesday.
The gunman began shooting at Berrendo Middle School in the town of Roswell around 7:30 am (1430 GMT) before being arrested.
"At this time, we can confirm that two students were injured, a boy and a girl, as well as a school staff member," New Mexico Governor Susana Martinez told reporters.
"One male victim, 12 years old, is currently in critical condition and is in Lubbock hospital. One female victim, who is 13 years of age, is in serious condition."
Martinez said the school employee quickly stopped the shooter when he "walked right up to him (the gunman) and asked him to set down the firearm, which he did."
"He was also assisted by a state police lieutenant who was dropping off his own child," she added.
The wounded school employee "didn't ask for any medical care because he wanted to continue to take care of the children that were in the gym," Martinez added.
New Mexico police chief Peter Kassetas said the shooter had probably acted alone.
"I believe we have the only individual in custody right now that's responsible for this," he said, adding that police had not yet uncovered a motive for the attack.
According to early reports, the gunman burst into a school gymnasium and pulled his weapon from a bag before opening fire.
The incident was the latest in a long line of US school shootings that have triggered a nationwide debate over gun control in the United States.
President Barack Obama called for tighter gun ownership laws in the aftermath of the December 2012 shooting at Sandy Hook Elementary in Newtown, Connecticut, where 20 children and six adult staff members were shot dead by a heavily armed gunman.