LONDON — Food delivery drivers blocked a busy central street here in rush hour this week, but their grievance wasn't pay or workplace rights — it was safety, and the very real fear of being attacked with acid.

In a country already on edge after three deadly terror atrocities, Britain is facing a new horrifying threat in the form of a wave of acid attacks that have occurred in locations across the country, affecting victims from all walks of life.

Jabed Hussain, 32, was sprayed in the face by two assailants who then tried to steal his bike as he delivered food in east London earlier this month.

“I’m just shocked, using acid to steal a bike?" he told reporters outside the British parliament during the protest. "What’s a bike worth?" My life is worth more than that."

He was one of five drivers assaulted in the space of 90 minutes — a terrifying spree that shocked London. At least one man was left with life-changing injuries, police said.

Jabed Hussain, a driver for UberEats, and a victim of a the July 13 acid attacks, during demonstration in Parliament Square in London on July 18, 2017. Niklas Halle'n / AFP/Getty Images

“I’m scared, many of my colleagues have stopped working after 8 p.m., we just don’t feel safe,” said another driver, Jake.

A petition demanding a crackdown on the sale and possession of corrosive substances has gathered almost half a million signatures. It was issued in the wake of an unprovoked attack on two young cousins in east London who were on their way to a 21st birthday party when they had acid thrown over their bodies as they got ready in their car.

Their local member of parliament, Stephen Timms, believes that "carrying acid without good reason should be a criminal offence, as carrying a knife is already." He also wants to licenses to be required for the purchase of sulfuric acid.

Acid assaults are, of course, not new a phenomenon. Experts say it has been happening for centuries and the tactic has been used by assailants from ranging gangsters to spurned lovers both in England and abroad.

But British authorities are worried at the indiscriminate nature of the recent surge in incidents, such as the attack on Jabed Hussain.

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“Acid attacks in the U.K. started at the birth of the industrial revolution ... this has been a problem since the 1700s," said Jaf Shah, Executive Director of Acid Survivors Trust International. "It was then a major part of gang on gang violence in the UK in the 1930s, 40s, 50s and 60s. But given the nature of the crime there’s a high chance it’s been heavily under-reported to authorities over the years.”

A 16-year-old boy was charged over the attack on Hussein. On the day the suspect appeared in a London court, the British parliament was discussing tougher sentencing for acid attack perpetrators, and new legislation on possessing corrosive substances.

Moped riders stage a protest in Parliament Square demanding that the government act on moped thefts in the light of recent acid attacks by assailants riding stolen mopeds, in London on July 18, 2017. Chung / Rex Features via AP Images

Illegal possession of knives and guns can carry prison sentences of four to five years in the UK, but a liter of sulfuric acid can be purchased for little more than $10 without ID.

Tighter regulations would be supported by the police. Detective Chief Inspector Mike West, the London Metropolitan Police’s lead for corrosive based crime, said: "We are working on a strategy on how to deal with corrosive attacks, including looking into possible restrictions around the sale of corrosive substances in conjunction with retailers, as well as the manufacturing process.”

London Mayor Sadiq Khan has also called for tougher sentencing of offenders, saying: "Acid attacks are callous and horrific... we need a new zero-tolerance approach as a country if we are to rid the streets of this scourge.”

Figures released by London’s Metropolitan Police show that the number of reported attacks in London alone rose 80 percent in one year, from 261 in 2015 to 458 in 2016. And over 200 cases have already been reported this year. Police forces in other parts of the country report figures in the hundreds as well.

Possible causes include recent crackdowns on knife and gun crime, with tougher sentences for possession of those particular weapons and crimes committed with them. It is also easier to obtain acid compared to other weapons, and much harder for police to prove malicious intent in anyone caught in possession of it.

Under-reporting of attacks in the era of gang violence, and media coverage of acid attacks are also suggested reasons for the increase.

Meanwhile, in parts of the world where acid violence is traditionally most prevalent — including India, Pakistan, Nepal and Colombia — the trend is heading in the opposite direction.

Acid Survivors Trust International data shows that in Pakistan 69 attacks were reported in 2016, down from over 300 a few years earlier, and while in Bangladesh 496 attacks were reported to authorities in 2002, the figure had dropped under 70 last year.

The impact of victims of these assaults speaking out has made a difference, Jaf Shah says.

“Survivors feel the tide is turning, and there is momentum, more survivors recognize they can be agents for change, taking on a stronger advocacy role, part of their recovery is to be fulfilled by doing something positive," he said.

Among those doing that is Daniel Rotariu, who in January 2015 was woken in the middle of the night by liquid being splashed across his face. His then-girlfriend poured half a liter of sulfuric acid over him after an argument.

“I ran to the shower, it got foggy, I panicked, called an ambulance,” he told NBC’s U.K partner ITV News this week. "I was in a coma for 5 weeks, hospital for 6 months, and had skin grafts to 33% of my body. I lost my right eye.” He says he’s speaking out to campaign for tougher sentencing on offenders. “I really hope the government will consider this, take action, otherwise there’ll be more victims like me.”

Acid attack victim Daniel Rotariu and girlfriend Anna Catanga ITV News

Daniel was speaking alongside one of the nurses who first treated him, Anna, who is now his girlfriend.

“What happened has changed my life as well, because it was destiny that we met, definitely right from the first day we got on so much and we talked and talked and ended up in a relationship, it was easy to fall in love with him he’s an amazing person," she said.

Four men were arrested Wednesday for possession of a suspected corrosive substance when their car was stopped and searched by police. Gloves, balaclavas and an acidic substance were found in the car.

Detective Inspector Michelle Peters said: "The impact of these substances on victims is terrible. Let me be clear, those found carrying corrosive substances will be arrested and they will be made to face the consequences."