A California teenager who wanted to commit a 'Columbine-style massacre' killed two people in a shooting at a library on Monday, police say. 

The gunman, identified as Bradley Scott Sayer, 18, opened fire at the Butte County Library in Chico, California around 5pm. 

An open 911 line allowed dispatchers to hear a number of gunshots and people screaming in the library, where a child was also injured alongside the two people who were killed. 

Sayer ran out of the library after being confronted by police, where two more officers then arrested him as he tried to flee, police said. 

Chico Police identified the gunman as Sayer on Tuesday, as he was charged with two open counts of murder. 

Authorities said they believe Sayer acted alone, and said he hoped to carry out a 'Columbine High School massacre-type of shooting. 

Police said Sayer tried to kill many more people in a random spree shooting, and said there is 'no indication Sayer had any prior relationship with or connection to any of the victims in the library at the time of the shooting.' 

Footage from the scene showed a huge police presence surrounded the library, but no officers fired their weapons or were injured as they took Sayer into custody. 

In a statement following the tragedy, Rep. James Gallagher, who represents the area, said: 'I am heartbroken by this senseless violence and am praying for the victims, their loved ones and everyone impacted by this tragedy.'

'Thank you to the brave law enforcement officers and other first responders who responded quickly to protect our community. Chico is strong, and we will stand together in the days ahead,' he said in the statement. 

California Governor Gavin Newsom also said in a statement after the shooting: 'Our hearts are with the Chico community tonight.

'We are grateful to law enforcement for their swift actions to secure the scene and take the suspect into custody. No family should have to endure a tragedy like this.'