CNN — Three teenagers – including a 14-year-old – were killed and another was injured during a shooting in Philadelphia Friday afternoon, police said.

Philadelphia police say officers responded to a report of a shooting around 3:30 p.m. Friday in the Lawncrest neighborhood northeast of downtown Philadelphia, where they found three victims.

The second victim – an 18-year-old male – was found on the front porch with gunshot wounds.

The third victim – a 14-year-old boy – was found inside the doorway of the home. Medics pronounced all three victims dead at the scene, police said in a report shared with CNN.

Another victim, a 16-year-old male, arrived at a hospital with a gunshot wound to his stomach. He is in stable condition, Philadelphia Police First Deputy Commissioner John Stanford told CNN affiliate KYW.

Police arrested two juvenile males – ages 15 and 16 – on firearms and related charges after a vehicle believed to be involved in the quadruple shooting was found.

The investigation is ongoing, police said.

The US has suffered at least 176 mass shootings in the first four months of this year, according to the Gun Violence Archive.

The nonprofit, like CNN, defines mass shootings as those in which four or more people are shot – not including the shooter.

CNN’s Holly Yan contributed to this report.