Police in riot gear today arrested a man after he gave himself up at a flat that had been besieged by officers hunting a knife attacker.

The 29-year-old man emerged from the front door and was led away by officers who will question him about an attack on Monday when two police officers were slashed across their faces.

The man, wearing a white baseball cap and sweater, was arrested more than two hours after a 16-year-old youth was able to leave the first-floor flat in Brighton through an open window.

The 13-hour operation to remove the man had involved more than 35 police officers and police dog teams.

Armed officers were on standby nearby.

After leaving the flat the man, who has not been named, was handcuffed.

His clothing, including an army jacket, was thoroughly searched before he was led to a waiting police car.

Chief Inspector Lisa Pearcey of Sussex Police said: "One of the police support unit officers engaged him in conversation and managed to convince him to leave the premises.

"There were no injuries, which shows that we took the right approach to this situation.

"From the manner of the operation today it was clear he wasn't going anywhere but with us."

He would now be taken to the Hollingbury Custody Centre, in Brighton, for questioning.

The siege began shortly after midnight when officers visited the flat in Whitehawk Way, Brighton.

Chief Inspector Pearcey said: "A man produced a knife and at that stage we withdrew."

The officers wanted to question a man about an attack on Monday in which PCs Luise Tait and Ian Upperton were attacked with a four-inch blade in Sillwood Place.

The officers were hunting a suspected burglar who had targeted a hair salon in Western Street, Brighton, the same evening.

PC Upperton was cut across his forehead while PC Tait's glasses saved her from serious injury when she too was slashed across the face.

The attacker, who was sprayed with pepper spray, escaped through a window, sparking the manhunt, which eventually led to the siege.

Shortly after 11am today, a 16-year-old youth left the flat and was led away for debriefing.

The youth, who is thought to live at the flat, was not arrested and police said they had little reason to fear for his safety.