A 75-year-old man stabbed to death yards from his home may have been targeted in a racially motivated attack, according to police.

Mohammed Saleem, who used a walking stick, was stabbed three times in the back as he returned home from prayers at his local mosque in Small Heath, Birmingham, on Monday night.

The blows were struck with such violence they penetrated to the front of his body.

The father of seven also had no defensive wounds in what has been described as a swift, vicious and cowardly attack by the man leading the murder investigation, Detective Superintendent Mark Payne of West Midlands police.

Officers want to trace a white man, aged 25-32, of medium height and build, spotted on CCTV footage running near the scene of the attack around the time it happened, just before 10.30pm.

Police also want to trace a seven-seat people carrier captured on CCTV, driving near the mosque with the two male occupants, both white and in their 30s, who are considered "significant witnesses".

In an emotional family appeal on Thursday, two of Saleem's daughters, Shazia Khan, 45, and Nazia Maqsood, 44, called for the attackers to hand themselves in. They tearfully described their father as a "widely respected member of the community" and "much-loved".

Payne said the possibility it was a racially motivated attack was "a significant line of inquiry" and a large number of detectives were working on the case. "To the attacker I say we will find you and we will bring you to justice," he added.

Khan, who lives in London, said she believed it was "a premeditated brutal attack, pre-planned, intended to kill".

She said: "I cannot see him having any enemies being so full of hate to do this to him. He was an old man – that's what he was. He had no other agenda in his life, it's unacceptable and we just cannot believe an attack like this would happen to him. We just cannot understand it.

"We have to walk past where he was killed and we can visualise it – we have to live with that for the rest of our lives."

Describing her father, Khan said he had worked with youths at the mosque and "was a really good role model and had a great sense of humour, very tongue in cheek". She said people from all walks of life had been paying their condolences.

Khan also had a message for her father's killers: "We don't know who carried out the attack – all we can say is you will be caught and you will be punished and justice will be done, legally.

"I hope they come forward. I hope that anyone who knows this man [seen in Wyndcliffe Road] or the driver in the car, there may be mobile phone videos made of the killing – we don't know. If there's any information people are sharing, every little bit of information is vital that will help catch the killer.

"It is unusual for someone of that description to be in that area. It may not be linked, we don't know, but every avenue has to be covered. We have to all pull together and get justice for my father and anybody else, because this could happen again."