Media mogul Rupert Murdoch on Twitter Saturday night called for more stringent gun control regulations, in the aftermath of a mass shooting in Aurora, Colo., which killed 12 people.

The shootings Friday in Colorado have led to renewed debate about gun control, but lawmakers and advocates say any new federal regulations are unlikely.

Authorities believe the shootings are the work of a lone gunman, James Holmes, 24, who is in custody. Holmes is believed to have entered a theater during a midnight showing of "The Dark Knight Rises" and opened fire.

President Obama is flying to Aurora on Sunday to meet with victims and local officials as the investigation proceeds. 

New York City Mayor Mike Bloomberg, a strong proponent of increased gun control, blasted President Obama and GOP candidate Mitt Romney after the shooting for not doing more to address the issue. 

“There are so many murders with guns every day — it’s just got to stop,” he said in an interview Friday. “No matter where you stand on the Second Amendment, no matter where you stand on guns, we have a right to hear from both of them concretely, not just in generalities — specifically, what are they going to do about guns?” 

Murdoch has not been shy about sharing his views on Twitter. Last month he took to the social media platform to criticize presumptive GOP nominee Mitt Romney’s campaign team. Murdoch advised Romney to “real pros” to help him defeat Obama.

He has also praised one-time GOP candidate and former Pennsylvania Sen. Rick Santorum on Twitter as the “only candidate with genuine big vision for country.”