One man was killed, three police officers were injured and a gunman was shot down after a hostage situation in what authorities are treating as an act of terror, for which Islamic State has claimed responsibility.

This is what we know so far.

The incident

• Police first respond to reports of explosion at 4pm on Monday at Buckingham Serviced Apartments in Brighton
• An employee of the apartments is found dead in the foyer. The man has since been identified as a Chinese-bown Australian
• A sex worker is called to the apartments and held hostage. She is later rescued
• Heavily armed police surround the building, shoot gunman dead when he bursts out firing his gun
• Victoria Police are treating the incident as a terrorist incident but say it isn’t believed to be part of a wider plot
• Following a raid at his home, police don’t believe he had accomplices and that there is an ongoing threat.

The gunman

• Named by Victorian police as Yacqub Khayre, 29, from Melbourne’s Roxburgh Park
• Khayre came to Australia as a young child with his parents, who are believed to have been Somali refugees
• Islamic State has claimed him as one of its “soldiers”
• Khayre was killed in the shootout with police
• Khayre was acquitted in the 2009 Holsworthy army barracks terror plot case
• He had been convicted of other assaults and was reportedly considered low risk
• He was on parole at the time of the incident

The victims

• An employee of the serviced apartments, a Chinese-born Australian man, shot dead. Police yet to name him.
• Three police wounded in gun battle, two in hospital, one with wounds to his face and neck
• Khayre was holding a woman booked through an escort agency hostage, she escaped unharmed

What’s being said

• “How was this man on parole? He had a long record of violence. A very long record of violence. He had been charged with a terrorist offence some years ago and had been acquitted. He was known to have connections, at least in the past, with violent extremism. But he was a known, violent offender. How was he on parole? – Prime Minister Malcolm Turnbull
• “We are treating it as a terrorism incident. The person has a background in relation to terrorism.”  – Victoria Police Chief Commissioner Graham Ashton
• “We are extremely concerned about terrorism…. we are very attuned to the threat of terrorism here in Melbourne.” – Victoria Police Deputy Commissioner Andrew Crisp
• “@VictoriaPolice sacrifice so much to keep us safe. They’ve shown that again tonight. Thoughts are with those injured and their colleagues.” – Premier Daniel Andrews on Twitter