A couple badly hurt in an arson attack may have been the victims of a drugs gang who got the wrong address.

Charlie Fern broke his back jumping from an upstairs window with his wife Chris in a desperate bid to escape the blaze.

Mrs Fern suffered extensive burns before leaping out of the first-floor window into their front garden.

Both were said to be "critical but stable" in Worthing Hospital's intensive care ward last night.

Police suspect the couple were targeted in a case of mistaken identity by a drugs gang which carried out a revenge attack.

The couple jumped 20ft as smoke and flames tore through their terraced property in Whitebeam Road, Durrington, Worthing, just before 1am yesterday.

Arsonists had poured petrol onto their front door and set light to it.

Neighbours were the first to spot flames and they immediately raised the alarm.

Two fire crews from Worthing found the front door and porch of the couple's home in flames.

They gave first aid to Mr Fern 66, and his wife, 59, until ambulance crews arrived.

Paramedics used "water gel" dressings which cooled the burns and provided pain relief before the couple were driven to hospital.

Neighbour described Mr and Mrs Fern, who have three grown-up sons, as "a lovely couple".

One said: "We all feel terrible about what has happened."

He heard what he thought was a clap of thunder and looked out of his window to see flames.

The neighbour ordered his family to evacuate and ran to the rear of the burning house. He said: "I smashed a window on the back door and shouted to Chris and Charlie to come this way."

At about the same time, the couple were jumping from their first-floor window.

Neighbour Gerald Williams, 70, who has known the couple more than 25 years, said: "I have never known any problem with them, so it's very surprising for something like that to happen."

Peter Prescott, 33, another neighbour, said: "It's really shocking. Vandalism happens quite often around here and there is always shouting and screaming in the woods."

Firefighters brought the flames under control in 20 minutes. A Home Office forensic scientist was called in later to investigate.

Worthing district fire commander Roy Barraclough said: "I am appalled by such a mindless arson attack."

Resident last night blamed drugs gangs and hooligans and said there had been five arsons in the area in recent months.

A £500 reward has been offered to catch arsonists who torched a community centre in nearby Shelby Road on June 3.

Chief Inspector Jason Taylor, Worthing's district commander, said: "We are treating this as an isolated incident. The house could well have been targeted or it may have been a case of mistaken identity.

"Anybody who starts a fire this way does so in the knowledge that it can cause injury or death.

"It is a very serious incident, one which I'm prepared to put a lot of resources into solving."

Anyone with information should call Worthing CID on 0845 6070999.