The mother of a Somali student hacked to death with a samurai sword lost another son just five months ago in a similar attack, writes dailymail.co.uk.

Fowsiya Abdi also lost a nephew who was fatally stabbed on the street in 2013. Yesterday the anguished mother called for anyone caught carrying a knife to be locked up.

She spoke out after the capital's deadliest night of the year so far, when two men were stabbed to death within a mile of each other in Camden, north London, and another three men were seriously wounded after being stabbed or shot.

Her son, aspiring accountant Sadiq Adan Mohamed, 20, rang her as he lay dying, leaving her a voicemail message begging for help, saying, 'I'm wounded,' just moments after he was attacked by a gang of four wielding a samurai sword about 10pm on Tuesday.

He died just under two hours after another Somali victim, 17-year-old Abdikarim Hassan, was stabbed to death as he visited a nearby corner shop.

She demanded tough action on knife crime as Scotland Yard Commissioner Cressida Dick said the 'senseless waste of life' cannot continue. Sadiq's brother Mohamed Aadam was fatally knifed last September in Camden, while his cousin, Mohamed Abdullahi, was stabbed to death in 2013.

Yesterday Mrs Abdi, 48, fought back tears at the family home in north London, as she recalled how her son rang her in his last moments.

She said: 'He left me a message that said 'I'm wounded, I got wounded'. But the police refused to let me see my son at the scene. After a while someone came to see me and said Sadiq was dead.

'I don't know who killed my son, I do not know why. But in September Mohamed was killed and now last night Sadiq was killed, and four years ago my nephew was too. They were all 20.

'It's unacceptable, I am now so worried for my other children, they all live in the same postcode. Sadiq was an excellent boy, he was very close to me and his family.

'He was at Middlesex University studying business and working part-time in Tesco. He did not do any drugs, or smoke, or drink alcohol. I cannot express how angry I am. I would like for anyone carrying a knife to be punished and taken off the streets and children who are excluded from school [for carrying a knife] to be stopped. If you lose a child it's a dark day.'

Mrs Abdi said her son, who dreamed of being a City accountant, had been targeted by a gang armed with a knife and gun two months before his murder on Tuesday night.

The mother of five said: 'On Boxing Day my son was attacked. A boy had a gun and a large knife. I took a picture of them but by the time I called the police they ran away. I was worried he would shoot me.

'On Tuesday night at 6pm Sadiq was here and he said, 'I'm going to the gym and then to see my friends, I'm coming back'. It's my biggest regret that I let him go, I am so shocked.'

Last September Mrs Abdi's elder son Mohamed Aadam was knifed to death outside a takeaway. In 2013 his cousin Mohamed Abdullahi was also fatally stabbed in the heart in a case of mistaken identity by a gang.

Yesterday the family released a statement saying: 'This is now the constant theme in our community. We are made to believe that the police are here to protect us, but how does a mother feel her kids are protected when she has lost two in the same vicinity within months? We have lots of questions and need answers. Somebody has to listen to us.' Police are trying to establish whether Sadiq's death was linked to the earlier death of the 17-year-old. One witness said of the attack on Sadiq: 'I heard a scream, a loud scream and I went to my window and he had been slashed with a samurai sword.

'People were screaming for towels, to throw down more towels.'

Meanwhile, Miss Dick said: 'I have spoken all too often at the anger I feel at the senseless waste of life. Today, two more families are suffering a terrible loss and my thoughts are with them. The frequency with which some of our young people are prepared to take each other's lives is shocking.'

Additional police patrols were sent to Camden and a Section 60 order giving police powers to stop and search people was put in place on Tuesday night.