Officers as well as paramedics were called to Pickwick House in Wingfield Street, Buckland today.
An air ambulance also landed at the nearby Buckland park.
A spokesman for South Central Ambulance Service said: ‘We are still at scene and being supported with the South East Coast Air Ambulance Helicopter and the Hampshire & Isle of Wight Air Ambulance critical care car.’
A Hampshire police spokeswoman added: ‘We are currently responding to a serious assault outside of Pickwick House, Wingfield Street, Portsmouth.’
One resident told The News that he was in ‘absolute disbelief’ about the ‘scary’ incident.
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