Two people were airlifted to hospital after a crash in Northamptonshire on Saturday.
The accident happened on the A361 between Daventry and the Newnham crossroads just after midday. The road was closed while emergency services attended.
Pc Dave Lee, from Northamptonshire Police Roads Policing Unit, tweeted the warning to drivers from his account, @Northants_RPU, that the road was like to be closed for some time.
Two air ambulances took two people to hospital, while another was taken by land ambulance.
Pc Lee added: “Because of the severity we have collected family and taken them to hospital to be with their loved ones.”
Details of the accident and how many cars were involved have not yet been made available.