• Video report by ITV News Midlands Reporter Ben Chapman

A man killed his sister and critically injured his mother in a knife attack at a flat before fatally turning the weapon on himself, police have said.

West Midlands officers used stun grenades to break into the Highfield Court flat in Wolverhampton after being alerted to the attack around 9.45am.

The attacker's sister, 33, died at the scene while her mother, aged 59, was left critically ill with serious wounds to her abdomen.

The man, aged 36, died a short time later of what police said were believed to be self-inflicted wounds.

The attacker's mother has undergone surgery but remains in a critical condition.

An officer received a minor injury to his arm after the attack in the first floor apartment was interrupted, while another suffered a leg injury in the operation.

"I knew something wasn't right, because I could hear banging and shouting," recalled Kelsey Nuttall, a witness at the scene.

Kelsey Nuttall, a witness at the scene. Credit: ITV News

"When I came out and went round the back there were two police officers running.

"I got told to move back because a 'mad man' is trying to stab people."

Three air ambulances were dispatched to a playing field close to the property. Credit: Kerry Siau

Wolverhampton Police Superintendent Keith Fraser, said: "Our officers knew there was an armed man behind the front door of that flat; they acted swiftly and with huge courage to quickly gain entry and later detain the man.

"Local officers, response colleagues and firearms officers were all involved in the operation.

"This is a truly shocking incident and our sympathies go out to the friends and family of those involved."

Police added that reports that the man involved in the incident had recently been released from a secure mental health facility were one line of enquiry they were pursuing.

Two people have died after the stabbing incident in Wolverhampton. Credit: ITV News

Armed officers were seen outside the block of flats as residents gathered after air ambulances arrived on a field in nearby East Green.

West Midlands Ambulance Service confirmed three air ambulances were sent to the scene along with three land ambulances.

A West Midlands Police spokesman earlier confirmed the incident was domestic-related and said no guns were involved.

A police car was also seen outside homes in the Merry Hill area. Credit: Kerry Siau

Detective Inspector Warren Hines later said: "We're working hard to get to the bottom of exactly what happened."

He appealed for anyone with information to contact him as an investigation begins into the events that led up to the attack.

The Independent Police Complaints Commission (IPCC) is investigating the incident after being notified by West Midlands Police.

Post mortem examinations are due to be held on Thursday.

Anyone with information is urged to call DI Warren Hines via the 101 number.