Police seized a rifle, a sawn-off shotgun and four handguns at various addresses in Croydon, Sutton and Southwark.
Yesterday six lethal firearms were seized in three separate operations by the Metropolitan Police Service’s Trident Gang Command.
A sawn off shot gun and a hand gun were recovered from an estate in Sutton and a handgun was recovered in Croydon.
A rifle and two handguns were seized in Southwark.
The firearms have all been sent for forensic testing and five men and a woman were arrested on suspicion of firearms offences.
Detective Chief Superintendent Dean Haydon, Head of Trident, said: "Trident officers continually target the suppliers of lethal firearms, protecting the public by removing guns from the hands of organised criminals and gangs.
“The Met has seized over 280 firearms and a large amount of ammunition from the streets of London this year alone.
"The number of shootings taking place in London has also significantly reduced, with 28 per cent fewer incidents than last year."
The Trident investigations were intelligence-led with the assistance of specialist teams and borough colleagues.
The operation was all part of Trident's ongoing efforts to target gang members and organised criminals operating in the south London area.