Three people have been arrested after a violent incident at Keelan Court, in quiet Richmond Road, just after midnight.
A 29-year-old woman from Southsea, a 32-year-old woman from Fareham. and 42-year-old man of no fixed address, have all been arrested on suspicion of grievous bodily harm with intent.
A police spokeswoman said a 28-year-old man was allegedly assaulted by the three people.
Here what we know so far
• Residents Speak of Shock & Disbelief
• Police Forensics Teams Still To Arrive
• Blood Throughout Apartment Block
Residents, trapped in their apartments as specialist scenes of crime officers have yet to arrive, they have spoke of their shock and disbelief at 'blood bath' scenes that greeted them this morning.
"It's truly beautiful here and I am extremely saddened by what has happened," one of the residents, who asked not to be named, told Spotted Portsmouth.
Keelan Court, in quiet Richmond Road, has been sealed-off for the second time in four years as police investigate a bloody incident.
The block of flats - once home to gruesome murderer David Hilder - has been cordoned-off by police this morning after blood was discovered sprayed all over the walls, floors, doors and elevator of the building. Sinister, bloody footprints can be seen trailing through all of the communal areas of the building.
"These photos are just downstairs. It's worse upstairs apparently. Our lovely home destroyed again," a resident said.
"It's all in the lift too. Foresnics police have still not turned up 12-hours later, so we are being forced into living in this stinking mess."
"The atmosphere here is one of shock and disbelief that this could happen again in our lovely quiet building," they added.
30-year-old homeless man David Guy was murdered and dismembered in a flat at Keelan Court in July 2012. 47-year-old Hilder, who is serving 12-years for the murder, is said to have cycled around Southsea with his one-time friend's decapitated head in the basket of his butchers bike. Parts of David Guy's body were discovered on Southsea seafront at the time.
Last night residents report hearing shouting, loud banging and doors slamming in the quiet neighbourhood just after 12.30am.
A 29-year-old woman from Southsea, a 32-year-old woman from Fareham. and 42-year-old man of no fixed address, have all been arrested on suspicion of grievous bodily harm with intent. A police spokeswoman said a 28-year-old man was allegedly assaulted by the three people.