Jean Charles de Menezes, shown in a 2001 identification photo, was a Brazilian national who was living legally in Britain. (AP Photo/Handout)

London's police chief has apologized after officers killed an innocent man whom they suspected of being a suicide bomber, but warned that similar incidents could occur.

Sir Ian Blair said it was a "tragedy" that Jean Charles de Menezes, a Brazilian national who was living and working legally in London, was shot and killed by police on Friday as he entered a subway train in south London.

On Saturday, London Metropolitan Police said they made a mistake, admitting that the 27-year-old electrician had nothing to do with the failed attempts to bomb three subway trains and a bus two days earlier.

"This is a tragedy," Blair later told Britain's Sky News television. "The Metropolitan Police accepts full responsibility for this. To the family, I can only express my deep regrets."


The victim's mother, Maria Otone de Menezes, centre, and his father, Matuzinho de Menezes, grieve in their home near Gonzaga, Brazil, on Sunday. (AP Photo)

But Blair defended the actions of his officers in the shooting, which took place two weeks after four suicide bombings in the city's transit system killed 56 people.

"What we have got to recognize is that people are taking incredibly difficult fast-time decisions in life-threatening situations," he said.

"What we have got to recognize is that people are taking incredibly difficult fast-time decisions in life-threatening situations." –Sir Ian Blair, London's police chief
"It wasn't just a random event and what's most important to recognize is that it's still happening out there."

The police commissioner told Sky News that the force won't change its policy of shooting to kill, in the head, when it comes to confronting suspected suicide bombers.

"There is no point in shooting at someone's chest because that is where the bomb is likely to be. There is no point in shooting anywhere else if they fall down and detonate it."


Alex Alves Pereira

Blair said he couldn't rule out the possibility of similar incidents as the hunt for suspects in Thursday's failed bombings and others involved in the deadly July 7 attacks.

"Somebody else could be shot. ...But everything is done to make it right," he told the television network.

The police force said officers saw Menezes emerge from a house that they had been staking out as part of the hunt for the bombers. They said suspicions were aroused because he was wearing an unseasonably bulky jacket and acting oddly, so they followed him.

They eventually chased him into the station and onto a train, where they shot five bullets into his head in front of stunned passengers.

'It's not believable,' victim's cousin says

Blair's remarks didn't answer many of the questions asked by Menezes' family and friends since the shooting.

His cousin, Alex Alves Pereira, said he doubted the police account. He questioned why police didn't stop Menezes before he entered the subway station, saying that his cousin would have obeyed police orders and had no reason to run.

"It's not believable, it's not believable," he told CBC News. "There is no explanation.

"He was a good person, he wouldn't do anything to anyone. ...He had nothing to hide from anyone. "

The Brazilian government demanded answers as well.

The country's foreign minister, Celso Amorim, was in London meeting with British officials on Sunday. He said Brazil stands with Britain against the people who carry out such attacks – with one caveat.

"Even in the fight against terrorism, we should also be cautious to avoid the loss of innocent life and that's what apparently happened," he said.

"It's now clear this was a peaceful and innocent person."

The independent Police Complaints commission will hold an inquiry into the shooting.