Three men have been taken to hospital following a serious collision which has closed the Foreglen Road near Claudy.
The collision was reported at 4.05pm.
A PSNI spokesperson said: “The condition of one of the men, a passenger in the Mazda car involved, is believed to be extremely serious.
“The other two men, the drivers of the Mazda and the second vehicle a Mercedes van, are not believed to have sustained any life threatening injuries.
“The Foreglen Road remains closed at present.
“Witnesses are asked to contact police by calling 101.”