A 20-year-old man was stabbed to death after he confronted teenagers he suspected of dealing drugs outside his home, a court has heard.

Omid Saidy chased down two males from outside his house near Parsons Green in south-west London but was knifed in the neck, the Old Bailey heard.

He had gone after the suspected dealers, along with his friend Oluwafemi Omotosho, known as Femi, who was on a moped.

Shafiq Smith, 19, and a 17-year-old, who cannot be named because of his age but was said in court to be from Shildon, County Durham, are both charged with Mr Saidy's murder.

Smith is further charged with the attempted murder of Mr Omotosho.

Prosecutor Timothy Cray told the jury the police investigation suggested the victims as well as the defendants were carrying knives.

He said: "Should they have chased the defendants? Absolutely not, dealing with drug dealers is the work of the police and the events show how quickly violence can spread if individuals try and take the law into their own hands.

"But did Omid need to die for the mistakes he made and did Femi need to be stabbed in the chest when he was lying on the ground? Those are the sort of very specific questions you'll need to focus on as you approach the evidence and reach your decisions."

He said: "Omid was angry that people were dealing drugs near (his) address."

He said the group had been asked to move on earlier in the day on October 16 but returned with their faces masked or wearing hoods that evening.

After an initial chase by the victim and his father, who the court heard had come outside to ask the group to go away, the defendants produced knives and were "waving them around", the court heard.

Mr Cray told the jury: "Omid was saying that he wasn't going to let it go, that he wasn't going to be intimidated."

CCTV footage played to the court showed Mr Saidy initially walking after the defendants as Mr Omotosho rode along on his moped.

A fight involving Mr Saidy, Mr Omotosho and the defendants took place under a railway bridge - not covered by CCTV - on Parsons Green Lane near the Tube station, Mr Cray said.

Mr Saidy was stabbed in the neck and pronounced dead at 8.30pm that night, the jury was told.

Mr Omotosho was stabbed while lying on the ground after falling off his moped but survived, the court heard.

The defendants, sitting in the well of the court, were 18 and 16 respectively at the time of the killing last year, the jury was told.

Smith, of Laitwood Road in Wandsworth, and the 17-year-old, of Shildon in Durham, deny all the charges.