Heroic bystanders spoke of the moment a young man “screamed in pain” as they fought to wash a corrosive substance from his eyes following a suspected acid attack in south London.

Scotland Yard said police rushed to Penge Lane, Penge, just after 1.30pm on Sunday to reports an 18-year-old man had had a “corrosive liquid” hurled into his eyes.

Staff at the nearby Himalyan Kitchen told the Standard how the man ran towards them crying for help and calling for his mum.

One worker, who asked not to be named, said: “I was talking to my customers and the man ran up, he was shouting ‘my life is gone, call my mum’.”

She told how quick-thinking customers doused the terrified victim’s eyes with a bottle of water before he was rushed to an upstairs flat to be rinsed off.

The employee added: “It’s terrifying, very scary. It is not a nice thing to happen, so cruel.”

Detectives said the man was taken to hospital suffering irritation to his eyes by paramedics from London’s Ambulance Service.

No arrests have been made and enquiries continue.

The attack came just 24-hours after Home Office documents revealed thugs caught carrying acid twice could face six months in jail.

The approach will be modelled on a system rolled out in 2015 for offenders repeatedly caught with knives, the consultation report said.

Minimum sentences were introduced for those aged 16 and over who are convicted of a second or subsequent offence of possession of a knife or offensive weapon.

The punishment is at least six months' imprisonment, which can be suspended, for adults. Young offenders face a minimum four-month detention and training order.

Judges must impose the minimum sentence unless there are particular circumstances relating to the latest offence, the previous offence or the offender which would "make it unjust to do so in all the circumstances".

The consultation document says it is not intended that "corrosive substance" will be defined in legislation as the offence "must be flexible enough to cover a range of possible situations: from someone possessing a corrosive substance in a public place that if used as a weapon can leave life-changing injuries; through to someone using a less harmful corrosive substance which if used as a weapon can still be very unpleasant to the victim but the effect is not lasting".