A mother who lost two sons to stabbings in London within the space of six months has said she fears for her remaining children.

“I’m feeling pain. I can’t sleep even, I can’t sleep tonight,” Fowsiya Abdi told BBC News. Her son, Sadiq Adan Mohamed, 20, died after he was stabbed in Camden on Tuesday night. His death came five months after the death of his brother, also 20, in September 2017.

Mohamed was the second victim of a fatal stabbing within two hours in Camden on Tuesday. The first, 17-year-old Abdikarim Hassan, was found with stab wounds on Bartholomew Road at about 8.30pm. He was pronounced dead at the scene.

At about 10.15pm police were called to another stabbing, just a few minutes’ walk away from the first, on Malden Road. Mohamed was given first aid, but died at the scene. According to a neighbour, he was on his way home from work when he was stabbed.

A witness was quoted by the BBC as saying that Abdi watched her son dying in the street from afar after she was refused permission to pass the police cordon. Her fear that it was her son was confirmed when she called his mobile and heard it ringing from inside the crime scene.

Abdi said that in the case of both of her sons, she believed it was a case of “wrong place, wrong time”. She said: “Please, I beg you, people who got a knife, children – stop please.”

Earlier the family said in a statement: “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.”

No arrests have been made and detectives have issued a fresh appeal for information and witnesses. Investigators are trying to find out whether the two fatal stabbings on Tuesday, and another earlier incident in which a person survived, are linked.