'It sounded like a war': At least five dead in Pittsburgh backyard shooting

At least 4 dead, 8 injured in Pittsburgh mass shooting. Photo: Twitter/Kelly Brennan

At least eight people have been shot and five killed in a mass shooting in the US city of Pittsburgh, Pennsylvania.

Police attended the scene in the suburb of Wilkinsburg, where residents said they heard more than 26 gunshots fired.

The incident began on Wednesday night just before 11pm when two gunman allegedly stormed a backyard party, Fox News reported.

Three women and one man were confirmed dead at the scene, and another woman died later at hospital.

One local told the Pittsburgh Tribune-Review she could hear the shots being fired.

"It sounded like a war," she said.

No further details of the suspect have been released. It is believed they are still at large.

More to come.