A crazed knifeman thought to be behind a string of terror attacks on women in Brighton struck again last night.

He hid in a darkened doorway of a pub before pouncing on a 20-year-old woman as she got off a bus in the town centre.

She went to use her mobile phone when he grabbed her arm and waved a knife at her, warning he would kill her if she screamed.

The victim struggled, broke free and ran to a nearby restaurant for help.

The attack was the third in three nights, and police are concerned they may have all been carried out by the same tanned-faced man.

Detectives are investigating two other attacks but they are not thought to be connected at this stage.

One happened last night when a 66-year-old man was repeatedly slashed with a knife.

On each of the attacks on women the knifeman has tried to abduct them but he has been foiled by victims struggling or when members of the public have come to their rescue.

Last night's assault happened outside the Quadrant pub near the Clock Tower at 10.40pm. The victim ran into a Burger King in nearby North Street where staff raised the alarm.

The attacker is about 30, 5ft 5ins, with dark eyes, large eyebrows and of Asian appearance. He wore a beige zip-up jacket and bobble hat.

Three women were grabbed on the streets of Brighton on Saturday.

The first incident happened in Clarence Square, near Western Road, at 4.30pm when an 18-year-old woman was grabbed from behind by a man waving a knife.

He threatened her and warned her not to scream as he pushed her along the road. Two members of the public came to her aid and the man fled.

He is 20 to 30, 5ft 8in, slim, spoke with a foreign accent, appeared Mediterranean, and wore a light-coloured top.

A man with a similar description pounced on a 27-year-old woman in nearby Marlborough Street at 7.20pm. He took hold of her arm and showed a knife but she broke free and the man made off.

He is also 5ft 8in, with a tanned complexion. He has short black curly hair and wore a scarf over part of his face.

A third attack on Saturday is not thought to be connected. It happened at 7.26pm in Preston Park Avenue, where a 32-year-old woman was waiting in a driveway.

The attacker passed her and later approached her from behind, holding her hand and arm. He dragged her 30ft down the driveway, warning her not to shout, but she screamed and members of the public came to her assistance.

The man punched the victim in the stomach before running off. He is 45 to 55, stocky, and wore a light-coloured jumper and jeans.

Last night's attack on a man happened in a loading bay in Black Lion Street at 4.30pm.

The victim suffered slash wounds to his face and back in what police said was a motiveless assault.

The offender is of Indian appearance, 30 to 40 and small build. He wore a maroon jacket and possibly a white hat.

Witnesses or anyone with information about any of the attacks should contact Brighton CID on 0845 6070 999 .