There were two reports in two days of a substance being sprayed from a car in the Stourbridge area, but West Midlands Police say they are not being treated as linked.
On both occasions the liquid was not believed to be corrosive.
First of all a substance was sprayed at a man from a car in Market Street, in Stourbridge town centre, on Friday.
Police, firefighters and paramedics were called to the scene at about 4.15pm, where a man in his 20s was treated by paramedics as a precaution and the road was cordoned off.
Then on Saturday, local police issued an alert on Twitter saying a vehicle had been going around the Stourbridge area throwing liquid at passers-by during the afternoon.
A spokesman for West Midlands Police later revealed the second victim was a teenage girl, saying: "Police received a call just after 3pm on Saturday from a woman reporting that two men in a black car by a roundabout at Mary Stevens Park had thrown a liquid at her 13-year-old daughter.
"The girl was not hurt and it's not believed the substance was corrosive.
"Enquiries are underway and police are trawling CCTV."
**Alert** small Black Vehicle seen around Oldswinford /Pedmore Stourbridge area 12/10/19 around 1500-1700hrs throwing liquid at passers by - can anybody provide further information to assist ongoing investigation ?— Stourbridge Police (@StourbridgeWMP) October 12, 2019
Regarding the first incident, a West Midlands Police spokesman said: "Police were called to reports of an unknown substance being sprayed from a passing car at a man on Market Street, Stourbridge at 4.15pm yesterday.
"Fire officers attended the scene and have confirmed this is not believed to be a corrosive substance.
"The man in his 20s was treated at the scene as a precaution."
Investigations are ongoing and anyone with information can contact police via the force website or by calling 101.