Detectives investigating a spate of knife-point robberies along a canal towpath have linked the suspects to four further attacks.

A total of eight incidents took place over five days, including four in one hour, in a spree spanning three boroughs.

On Monday (August 7) police issued an appeal for information about a gang of youths who carried out late-night muggings alongside the River Lea near Lee Valley Marina Springfield opposite Walthamstow Marshes.

In one such attack, the robbers held a kitchen knife to their victim’s throat

Detective Inspector Paul Ridley of Hackney CID who is leading the investigation said: "Four of the crimes occurred in under an hour, in a spree spanning Hackney, Tottenham and Waltham Forest, demonstrating the brazen nature of these robbers.

"In some offences, the suspects have used unnecessary threats and violence, attacking victims after they had handed over property.

"There have been increased patrols in the affected boroughs and activity has taken place to reassure the community, including warning local residents, many who have boats moored on the river.

"I cannot discount that there may be other victims who have yet to contact police - I would urge them to come forward and provide us with any information they have; this may prove vital to our investigation."

The first robbery happened at 10.15pm on Tuesday, August 1 when a 31-year-old man was cycling along the path and was approached by four masked men on bikes.

The men, who are all described as black and aged between 18 and 23, assaulted him and threatened to stab him before taking off with his phone and wallet.

Just minutes later a second man, aged 39, was attacked by a group of men at High Hill Ferry, opposite Walthamstow Marshes.

They stole a bank card, watch, silver crucifix necklace and his house keys.

At 11.30pm the following day, Wednesday August 2, three men aged in their early 20s were walking close to the Springfield Marina.

They were approached by three suspects on bikes who assaulted them and held a kitchen knife to one man’s throat.

Their phones and bank cards were stolen.

The following day, Thursday August 3, at 11.40pm a 32-year-old man was attacked by a gang of five black youths who robbed his mountain bike.

The next incident happened less than half an hour later when a 39-year-old cyclist was targeted by a masked gang on bikes. They left empty-handed.

Minutes later a 30-year-old man was assaulted and had his phone and wallet robbed by four youths wearing balaclavas.

He described the suspects as black, aged between 16 and 19, and between 5ft 11inches and 6ft 2inches tall. One of the males had a fur hood liner in his jacket and another was seen to flee on an orange coloured mountain bike.

Shortly before 00.30 on Thursday morning a 26-year-old man and a 25-year-old woman were attacked by three men near Yarmouth Crescent, Tottenham Hale.

After one suspect tried to pull the woman’s handbag from her, she fled and hid in undergrowth. The male victim was punched to the ground and had his phone and wallet stolen.

The final incident happened at 10.25pm on Saturday August 5 when a 28-year old man was targeted by three suspects on bikes. They left empty-handed.

One of the suspects is described as a white male, 5ft 10inches tall, aged in his late 20s, of stocky build and wearing dark clothing.

Anyone with information is asked to contact Hackney CID via 101 or via Twitter @MetCC quoting operation name 'Glanford'.