Initial reports from Kharkiv, the second largest city in Ukraine, claim the car involved was an Lexus SUV.
Images taken by witnesses show a large number of police cars and at least three people lying motionless in the street.
Another picture shared on Twitter shows the smashed up Lexus stretched sideways across the road.
Local media is reporting the car collided with a Volkswagen Touareg in Sumskaya Street, lost control and span into crowds walking along the pavement.
A woman has been arrested on suspicion of violating traffic safety rules, Stud Media reported.

vCard.red is a free platform for creating a mobile-friendly digital business cards. You can easily create a vCard and generate a QR code for it, allowing others to scan and save your contact details instantly.
The platform allows you to display contact information, social media links, services, and products all in one shareable link. Optional features include appointment scheduling, WhatsApp-based storefronts, media galleries, and custom design options.
More to follow.