DETECTIVES probing a spate of serious crimes committed in Suffolk in less than 24 hours today stepped up their investigations after issuing an e-fit and an appeal to the public.

DETECTIVES probing a spate of serious crimes committed in Suffolk in less than 24 hours today stepped up their investigations after issuing an e-fit and an appeal to the public.

Their move comes after two men staged a knife-point car-jacking in Wherstead, a lorry driver was beaten by two men posing as police officers in Claydon, and a crossbow-wielding robber stole cash after raiding a bookmaker in Ipswich's Ellenbrook Road.

The trio of incidents took place between 1pm on Monday and 12.15pm on Tuesday.

Suffolk Police today issued an e-fit of a man they want to trace in connection with the car-jacking in Wherstead, where a blue Subaru Impreza, registration EY07 MTO, was stolen.

The driver of the car had parked in a lay-by in The Street and was having a cigarette at around 1.30pm, when a black N-registration Honda Civic drove past, returning soon after.

A man got out of the Honda, held up a knife and demanded the driver hand over his keys. The driver did so and the cars drove off towards the A137.

The car-jacker was white, in his late 20s to mid 30s, of slim build, between 5ft 11ins and 6ft 1ins, with short dark brown or black hair and stubble. He spoke with an Eastern European accent.

The Honda driver was male, white and was wearing a cream-coloured hooded top with the hood up and a light brown baseball cap.

Meanwhile, detectives today renewed an appeal in connection with the incident at Claydon on the A14.

At around 3.25am a lorry driver was driving along the Stowmarket-bound carriageway when he noticed a car with a blue light inside behind him.

The lorry driver pulled over in a lay-by and got out of his cab. Two men got out of the car, a black Vauxhall Vectra SRI and one asked if he knew why he had been stopped. One of the pair then assaulted the lorry driver while the other got into his cab.

They eventually returned to their car and made off. The lorry driver suffered minor facial and back injuries, while damage was caused to the interior of his cab.

The first man was white, in his late 30s to early 40s, of slim build, around 6ft, with dark wavy short hair and was wearing a long sleeved high-visibility jacket, a dark coloured t-shirt and dark trousers. He spoke with an Essex or London accent.

The second was also white, in his late 20s or early 30s, of stocky build, between 5ft 8ins and 5ft 10ins, with short dark hair and wore similar clothes.

Those with information on either incident, or the robbery at the bookmaker, should call police on 01473 613500.

Detectives believe that the Claydon attack was an isolated incident.

However they have issued some basic steps checks for drivers to ensure that the unmarked car that is signalling for them to stop is a genuine police vehicle:

n. Continue to drive sensibly and do not increase your speed;

n. Stop when it is safe to do so, but remain in your vehicle with the doors locked until the officer approaches your window.

n. Wind the window down sufficiently and ask the officer for their police identification warrant card which they should have on them at all times;

n. Exercise caution particularly in remote areas or during darkness. Under these circumstances the motorist is within their rights to proceed to the nearest lit area or to the nearest police station before stopping.

n. If you are still unsure, then call Suffolk Constabulary on 01473 613500 to check the officer's details.