Witnesses have described the moment gunmen opened fire on teenage revellers at a New Year's Eve party, leaving two people seriously injured.

A 22-year-old woman was shot in the leg at the house party in Waddon New Road, and an 18-year-old man was shot in the chest minutes later in a nearby road.

Police initially said a third victim had walked into St George's Hospital later that morning with a gunshot wound to the abdomen, but now believe there were only two casualties.

Trident detectives are linking both shootings, which happened at 4.30am and 4.45am on January 1.

One neighbour, who did not wish to be named, said the attack happened after an illicit New Year's Eve party in the empty house spiralled out of control.

Terrified partygoers smashed their way through a fence at the back of the house to escape.

Minutes later police and ambulance crews found an 18-year-old man who had been shot in the chest during a fight at the junction of Church Road and Reeves Corner.

It is the second year in a row that new year celebrations have been marred by violence in the borough.

A year ago a gunman went on the rampage in a Thornton Heath pub, killing one man and maiming his brother.

Neighbour Mary Sepamalai, who has lived in Waddon New Road for 3 years, said she was stunned to hear there had been a shooting in the street.

She said: “It’s so nice and quiet - this is the first time something like this has happened while I’ve lived here.

“We came back from church at about 1.30am and the party was going, but we slept through the whole thing - we didn’t even hear a gunshot.”

Another neighbour described the moment the gunmen opened fire.

She said: “Another group of kids had come round to have a fight, and they were shooting from outside into the house and girls were screaming.

“These guys had driven up outside and stopped, then got out with a cricket bat and started throwing stones to smash the windows.

“I had a panic attack when I realised what was going on.

“The girl who got shot managed to get across the road to another house, and they called an ambulance.

“They had been making a lot of noise but we just thought it was a regular party at first.

“There were about 50 people there and you could smell the weed, there were drugs there as well as drinking.

“It’s been a month since the people moved out of the house.

“The police said they didn’t live there and shouldn’t have been there, but they didn’t break in so they must have had a key.”

Police cordoned off the road until 5pm as forensics teams searched the property.

A year ago a pub landlord's two sons were shot by a gunman after an argument in Thornton Heath.

Darren Deslandes was killed and his brother Junior Deslandes was shot three times but miraculously survived.

Gunman Saturday Hassan is serving 37 years for the murder of Mr Deslandes.

-Four teenagers arrested on suspicion of attempted murder in connection with the shootings have been released on bail until March.

The two 16-year-olds and two 17-year-olds were held at a south London police station after the attack on January 1.