The pedestrians were injured shortly after 15:00 and have been transferred to hospital in Glasgow.
A woman and three children have been taken to hospital after they were hit by a car in South Lanarkshire.
The Scottish Ambulance Service said 10 crews were dispatched to the scene in Carluke, shortly after 15:00.
It is understood those injured are a mother in her 20s and three children, the eldest of whom is seven.
All four have been taken to the Queen Elizabeth University Hospital in Glasgow but no details about their conditions have been released.
Police said emergency services remained at the scene and local diversions were in place. The A73 is currently closed between Glamis Avenue and Clyde Street.
Insp William Broatch, from Motherwell Road Policing Unit, said: “Around 15:10, police were called to James Street in Carluke, at the junction with Kirkton Street, following a report of a road crash involving a car and four pedestrians – a woman and three children.
“The pedestrians are all being conveyed to hospital for treatment.
“Emergency services remain at the scene and local diversions are in place. Anyone with information on the incident can call police on 101, quoting incident 2110 of 27 October.”
Local MSP Mairi McAllan, who represents the Clydesdale constituency, said she was “deeply worried” about the reports coming out of Carluke.
She said: “My team have been in touch with local police offering whatever help we can give.
“I want to thank the emergency services who’re on the scene, and in the meantime I’m just praying like everyone else for good news that no one’s seriously hurt.”