POLICE are closing in on a gang which brutally murdered two brothers in south London on Saturday night.

Mohammad and Hayder Ali, 23 and 24, were pulled from a white Mercedes van and stabbed to death in Fircroft Road, Tooting, in the early hours of Saturday morning by a gang of about 15 Asian men.

Police believe the gang surrounded the van, smashed its windscreen and dragged the Pakistani brothers out after an argument broke.

The brothers were then stabbed and died later at St George's Hospital. A third man, the driver of the van, was uninjured.

One man was arrested at home in Tooting today and another two at a business in Battersea.

While two men were yesterday arrested at a home in Balham and a third voluntarily attended a south London police station.

In total, 13 men have been arrested over the double murder, eight of whom remain in police custody.

Detective chief inspector Mick Duthie, who is leading the investigation, said: "We believe that about 15 men were in the group that attacked the Ali brothers and I am appealing for them to come forward.

"A large number, and variety, of weapons including knives and baseball bats have also been recovered within the vicinity of the scene, and are currently being forensically examined.

"This attack on two young men has resulted in a family losing not one, but two sons, and I appeal to the local community and anyone who may have information to continue to assist us in our attempt to bring those responsible to justice."

Detectives want to speak to anyone who was near Fircroft Road or Upper Tooting Road just after midnight on Saturday morning.

Anyone with information should call the incident room 020 8721 4155 or Crimestoppers anonymously on 0800 555 111. They are particularly keen to hear from anyone who was in the vicinity of Fircroft Road or Upper Tooting Road at the time of the incident.