The brother of execution-style murder victim Yasser Hussain Nazir told this week how his family had received chilling telephone threats a week after the 16-year-old boy's death.

Mohammed Sadique, 24, said: "My younger brother was threatened. Those responsible wanted to let us know they think they are heroes. They are not heroes. They don't feel sorry about what they've done.

"They wanted to let us know what they could do."

Yasser was shot dead on September 5 as he pulled into a petrol station, in Haworth Road, Heaton, Bradford, in a white Vauxhall Astra.

His killer, who was in a green Honda Accord owned by a Skipton man, fired a single shot from a long-barrelled gun through the windscreen into the teenage victim's head.

Yasser, of Chatsworth Street, Keighley, drove off but was hit again and died at the wheel. Two other men in the car were unhurt.

His brother said the family believed Yasser was a victim of mistaken identity.

"The family's very depressed. We can't believe what happened and will never get over the fact he's gone," he said.

"It's the way he has gone -- everybody has to go one day but what happened to Yasser was terrible. We can't believe it."

He said he believed there were people out there who had information and he urged them to come forward.

"These people could strike again and nobody knows whose name will be on the bullet.

"He (Yasser) was only 16. What harm can a 16-year-old boy do to anybody.

"We must have the information about who did this to our little brother.

"Please don't protect the people who have done it. Please tell the police," added Mohammed.

He said Yasser was passionate about cars and was a fan of Manchester United. He hoped eventually to deal in cars as a job, or even to play football.

Mohammed said he used to buy a Manchester United shirt every year and they used to enjoy playing football together.

Det Supt Phil Sedgewick, who is leading the hunt for the killer, appealed for anybody who had information about the green Honda to come forward.

Anyone with information should contact the police on 01274 376225.