Craig Lawson (left) and Steven Garland

Their car left the A92 near Ladybank after the collision, which took place shortly before 2100 GMT on Monday.

The exact cause of the crash which killed driver Steven Garland, 17, Craig Lawson, 17, Mona Halliday, 16, and Lisa Donaldson, 16, is not yet known.

But Chief Inspector Bob Farmer said initial inquiries "support the theory that speed was a significant factor".

Mr Farmer, from Fife Constabulary's Road Policing Department, said: "It is of considerable concern to everyone in Fife Police, particularly those involved with road safety, that we continue to suffer accidents which take the lives of our young people away.

Mona Halliday (left) and Lisa Donaldson

"Much has been done to promote road safety in Fife, particularly in informing young people of the pitfalls of driving at speed and testing their capacity behind the wheel on public roads."

He added: "I would implore everyone who can exert influence over young people to join the Pass Plus scheme run by Fife Police to allow them to develop their skills in a controlled environment.

"They should also be urged to drive carefully and with consideration for all road users and either within the speed limit or the correct conditions for the road.

"It might be enough to prevent another needless fatality on Fife's roads."

Flowers have been laid near to the scene of the crash

The 16-year-old victims, from Pitlessie, were both fifth year pupils at Bell Baxter High School, Cupar. Mr Lawson, from Ladybank, was an apprentice plumber and Mr Garland, from Pitlessie, was a student at Fife College.

The group were travelling in a Ford Fiesta which left the road and crashed into a field after being in collision with a Volvo just north of the Eden Bridge. The Volvo driver was uninjured.

The road was closed to allow the cause of the crash to be investigated.

Local councillor Donald Lothian described the accident as an "absolute tragedy".