A man wielding a knife was locked in a taxi by its driver – and police believe he tried to get into a woman’s car at High Wycombe traffic lights 10 minutes earlier.

The man escaped by smashing the taxi window in Cressex Road yesterday afternoon.

Police believe the same man tried to get into a woman’s car at Handy Cross roundabout 10 minutes before. She was on her own in the vehicle.

It is the second reported “knife-jacking” in the town in a week and police believe the incidents may be linked.

A statement by Thames Valley Police said: “A lone female was stationary in her car at the traffic lights at Handy Cross roundabout at 1.15am on Sunday 23 November when a male approached her front passenger door and tried to get in.

“He then frantically banged on the window in an attempt to enter the vehicle but the car then drove away.”

A man then “entered a taxi, produced a knife and started to search the taxi for items to steal”.

It said: “The taxi driver managed to escape locking the offender in the vehicle. The offender then managed to smash a window and made off towards the Shell garage after setting fire to some paperwork in the taxi.”

He is described as white, 17 to 18-years-old, skinny with short mousey brown hair, and wearing a scarf over his face and a dark blue hooded jacket with the hood up.

On Monday police said a man a tried to knife-jack a car then threatened a taxi driver before burning it out in a residential street.

He jumped into a VW Golf in Marlow Road, High Wycombe at 9.45pm, police said.

He forced the driver at knife-point to drive to the HSBC bank in Common Road, Flackwell Heath to get money.

The driver managed to escape and the man then approached a taxi driver in Old Kiln Road who was driving a silver Peugeot 407, police said.

He demanded money and forced the driver out of the vehicle.

This vehicle was then driven past High Wycombe hospital towards Desborough Avenue and then abandoned and burnt out in Conifer Rise, High Wycombe.

DC Andy Powell-Williams, investigating both incidents, said: “While I am keeping an open mind at this stage it is possible that these robberies are linked.”

He said: “I would always advise drivers to lock the doors of their vehicles while driving alone at night.

"If possible pace your approach to traffic lights to avoid having to come to a complete standstill.”

Anyone with information about either incidents can contact DC Powell-Williams on 0845 8 505 505 or call Crimestoppers anonymously on 0800 555 111.