It happened in Caerphilly County in the early hours of this morning.
One person has life threatning injuries after a crash in the early hours of this morning in Caerphilly county.
It happened just after midnight on on the A472 between Tredomen and Nelson.
Two cars - a VW Polo and a Mini - were involved.
One driver has been taken to the Heath Hospital, Cardiff with life threatening injures.
Gwent Police is appealing for any witnesses to come forward.