Two killed in two separate US university shootings

Two people have been killed in two separate shootings at universities in Texas and Arizona, just hours apart.

One person was killed and three more injured in the first shooting at Northern Arizona University early on Friday, which involved fraternity members.

A few hours later, a shooting at a student complex near Texas Southern University left one person dead.

Police have identified the Arizona gunman as Steven Jones, an 18-year-old first year student at Northern Arizona University.

He has since been charged with first-degree murder and three counts of aggravated assault.

Jones told police that he was approached and assaulted by a group of men. He fled the scene, picked up a gun from his car and shot at the men when they caught up with him. One of them, Colin Brough, was killed, while the other three students are being treated in hospital.

Witnesses told police that the three victims were unarmed, and representatives from the Delta Chi fraternity's national organisation said its members were involved in the confrontation.

“This is not going to be a normal day at NAU,” Arizona university president said after the shooting. "Our hearts are heavy."

Houston police have detained two people as suspects over the Texas shooting, while police spokesperson Jodi Silva confirmed that a third suspect is still at large.

The attacks came after US President Barack Obama visited families of victims of a separate college shooting in Oregon last week that left nine people dead.

Upon arrival, he was jeered by gun-rights activists who oppose his calls for tougher gun law. Many were openly carrying handguns to hammer home their message.

After a private meeting with the families, Obama said he had "strong feelings" about gun control, adding:

"We are going to have to come together as a country to see how we can prevent these issues from taking place,” he said.