(Cover) - EN Showbiz - Celebrities have expressed their grief over Friday's fatal shootings at a Colorado movie theatre.

James Holmes opened fire as the new Batman movie The Dark Knight Rises was screened at a cinema in Aurora, Colorado, at midnight today.

The 24-year-old former neuroscience graduate student killed at least 12 people and has injured more than 50.

Hollywood stars are disgusted by the atrocity and took to Twitter to express their sentiments.

"I'm terribly sad to hear about what happened in Aurora, Co. last night, my thoughts and prayers are with the victims of this tragedy," Zooey Deschanel tweeted.

Rock of Ages star Julianne Hough is equally dismayed.

"My love & prayers are with all the families that have been affected by the horrible, unspeakable torment from last nights shooting! #BeKind," she wrote.

"Praying for the victims and families of those involved in the shooting in Colorado. My heart is broken. So awful. God Bless... (sic)" Jessica Simpson shared.

Authorities confirmed in a press conference that they "are not looking for any other suspects" because they are sure that James "acted alone".

FBI and police have evacuated five apartment blocks surrounding James home as his apartment has been booby trapped.

Guns, gas and tripwires have been meticulously placed around rooms and can be easily detonated.

Officials are actively trying to secure the residence. (C) Cover Media