10 shot, 3 fatally, when 'multiple' gunmen open fire at large Philadelphia party, police say

More than 100 people were at the scene for a party, police told WPVI.

Ten people were wounded, three fatally, when multiple shooters opened fire early Sunday at a party in Philadelphia, police told Philadelphia ABC station WPVI.

The mass shooting unfolded around 2 a.m. on the 1200 block of North Alden Street in the Carroll Park neighborhood of West Philadelphia, where a party attended by more than 100 people was taking place, police said.

When officers arrived, they found victims suffering from gunshot wounds and multiple spent shell casings scattered in the area, Philadelphia police Inspector D.F. Pace said during a news conference at the scene.

"It appears that there were multiple shooters. It's unclear at this time how many. But we have counted at least 25 to 30 spent shell casings at this time," Pace said. "We're not sure if it was a block party or just simply a group of individuals who were invited from other parts of the city. It's just not clear at this time."

Pace said a total of 10 people were shot, including the three who were killed.

One gun was recovered at the scene, officials said.

Investigators were working to identify those involved in the shooting. No arrests have been announced and the names of the victims killed were not immediately released.

All of the shooting victims are adults in their 20s and 30s, police officials told WPVI.

This is a developing story. Please check back for updates.