One victim was reportedly left with life-changing injuries after moped riders targeted takeaway delivery drivers in the north and east of the city.
"They were shouting and I gave them water and they were washing their faces".
West Midlands Police said that they are issuing guidelines for dealing with corrosive liquids in accordance with national police policy and 1000 acid relief kits were given to Met Office police officers.
Police have been called to reports of an acid attack in East London. The shopkeeper added: "They were pouring water over themselves and it had got into their clothes. Their faces and their legs were all burnt". One of them was saying: "Put the water in my jeans".
He said a crime scene remained in place in the area.
Pictures on social media show firefighters on the scene at Roman Road, as well as a jacket with the material eroded.
"Officers were flagged down in the area at 7pm on Tuesday by the two males who are believed to be aged in their late teens".
Police, ambulance and fire services responded to the scene to investigate the suspected acid attack.
London Ambulance attended the scene and the pair were taken to hospital for treatment.
No arrests have been mande and enquiries are ongoing.
The incident is the latest in a shocking spate of attacks in the capital in recent weeks. The attack was the first of five in a single evening.
This is an image made available by Sarah Cobbold of the scene of an acid attack in London on July 13, 2017.
Shawkat and his friend staggered into a shop, screaming in agony for help after the liquid was thrown on them around 7pm that day.
Jameel Muhktar, 37, and his 21-year old cousin Resham Khan received life changing injuries in an acid attack in June while they were in a vehicle. On Easter Monday, acid was sprayed at a crowded east London night club, leaving two people partially blinded and others disfigured. It includes protective gear and five-litre bottles of water, to allow officers to administer immediate treatment to victims.