Five women were taken to the hospital after two people on a moped threw acid on them near 105 Wilkinson Avenue in Jersey City on Monday night, according to NBC News and PIX11.

The substance used was likely sulfuric acid, News 12 New Jersey reported. Sulfuric acid burns skin immediately when it makes contact, and the damage gets worse the longer it stays on the body. Officials have not said how serious the victims' injuries are.

This type of attack—using acid thrown from a moving vehicle—has happened in other cities too. Police say it creates special problems for investigators. The attackers get away fast on their moped. The acid itself is easy to buy. And by the time anyone realizes what happened, the suspects are already gone. Similar attacks have occurred in the United Kingdom, where police eventually made it harder to buy acid and gave longer prison sentences to people who throw it.

As of June 16, Jersey City police have not identified the suspects or said what the motive was. The investigation is still happening. It is not yet clear whether the attack was aimed at these specific women or was random.

Police will focus on three main tasks: finding camera footage from the street, identifying the moped using its license plate or what it looked like, and figuring out where the acid came from. Jersey City has many security cameras set up around the city. With this kind of surveillance, police often find suspects fairly quickly.

The hospital caring for the victims and how they are doing have not been announced yet. Treating acid burns means washing the skin right away and sometimes surgery to fix the damage. Recovery takes time and costs money, which is why helping victims get the care and support they need matters.

No one has been charged yet.