• An innocent Brazilian electrician was shot dead by police on Friday

• Police have warned that more people may be shot

• Muslim leaders expressed concern that their community will be targeted

Key quote

"We have to take this tragedy, deeply regret it and move on to the main investigation which is proceeding at an extraordinary pace." - Sir Ian Blair, Metropolitan Police Commissioner

Story in full POLICE warned yesterday that their shoot-to-kill policy would be applied across the whole of Britain and that more people might die at the hands of armed officers as a result of the investigation into the London bomb attacks.

As a third man was arrested in connection with last Thursday's failed attacks, Sir Ian Blair, the Metropolitan Police Commissioner, apologised to the family of the innocent Brazilian electrician shot dead by police on Friday but said the killing would not change the way police operated.

Jean Charles de Menezes, 27, was shot five times in the head as officers pinned him to the floor on an Underground train at Stockwell, south London. It later emerged he had no involvement in the bombing but had merely lived in the same block of flats as a suspect in the investigation.

Yesterday, his family called the police "stupid and incompetent" and the Brazilian government said the British had made a "lamentable mistake".

Sir Ian said he regretted the killing but warned that Mr de Menezes might not be the last to die. "Somebody else could be shot," he said. "But everything is done to make it right. This is a terrifying set of circumstances for individuals to make decisions."

He revealed that, despite there having been no change in the unarmed status of Britain's police, one in ten officers in the Metropolitan force now routinely carried a firearm.

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

"It wasn't just a random event and what's most important to recognise is that it's still happening out there. There are still officers out there having to make those calls as we speak."

Last week, police denied they were operating a shoot-to-kill policy, but Sir Ian performed a U-turn over that stance yesterday. He said a "shoot-to-kill-in-order-to-protect policy" was in place across the country, not just in London. "I think we are quite comfortable the policy is right but these are fantastically difficult times," he said.

"We have to take this tragedy, deeply regret it and move on to the main investigation which is proceeding at an extraordinary pace."

The officer who fired the shots that killed Mr de Menezes aimed for the head because police have adopted a new way of dealing with suicide bombers. "There is no point in shooting at someone's chest because that is where the bomb is likely to be," Sir Ian said. "There is no point in shooting anywhere else if they fall down and detonate it. It is drawn from experience from other countries, including Sri Lanka. The only way to deal with this is to shoot to the head."

But he said officers would still try to restrain suspects without resorting to lethal force.

Mr de Menezes was shot after leaving a small block of flats in Tulse Hill, south London, which was under surveillance. He caught a bus the few miles to Stockwell Tube where he was challenged by officers but, according to witnesses, bolted down an escalator.

Two men were in custody at London's high-security Paddington Green police station after being held in Stockwell in connection with the 21 July attacks and last night a third man was arrested by police in Tulse Hill under the Terrorism Act.

Earlier, police carried out a series of controlled explosions on a suspicious package, found hidden in bushes at Little Wormwood Scrubs, north-west London, which has been linked to the devices found last week on three Tube trains and a bus. It was taken away for further examination and searches continued at the scene.

Last night, Charles Clarke, the Home Secretary, gave his backing to the police handling of the investigation, insisting he had nothing but "praise and admiration" for the way they had done their job.

However, the killing of Mr de Menezes threatened to start a diplomatic row between Britain and Brazil. The latter's foreign minister, Celso Amorim, spoke yesterday to his British counterpart, Jack Straw, to demand an explanation for the shooting.

"The Brazilian government and the public are shocked and perplexed that a peaceful and innocent person should have been killed," he said. "Brazil is totally in solidarity with Britain in the fight against terror, but people should be cautious to avoid the loss of innocent life."

He said Mr Straw had assured him the killing would be the subject of a full investigation.

Brazilian outrage at the shooting will, however, be regarded with some scepticism by human rights groups, given the record of its own police. An Amnesty International report on Brazil last year raised concerns about police killings, extrajudicial executions and "death squads". Official figures show that in the previous year in São Paulo alone, police killed 915 people, while 1,195 were shot dead in Rio de Janiero. Amnesty reported that the killings were rarely investigated and were often registered as "resistance followed by death".

Mr Straw said he "deeply regretted" the killing of Mr de Menezes, but said it was essential that police were able to deal effectively with the threat of a suicide attack.

"We have to ensure that clear rules are operated but we also, tragically, have to ensure that the police do have effective discretion to deal with what could be terrorist suicide outrages about to take place."

The former foreign secretary, Robin Cook, said the death of Mr de Menezes had been a "serious blow" to relations with Brazil and police would have to look again at the shoot-to-kill policy.

Muslim leaders expressed concern that their community would be targeted after police identified the four 7 July bombers as British Muslims.

Azzam Tamimi, of the Muslim Association of Britain, said: "To give licence to people to shoot to kill just like that, on the basis of suspicion, is very frightening."

He said: "They will not want to have anything approaching a repeat of that and I am quite sure that they will be tightening up the guidelines and the rules of engagement to make sure it doesn't happen again."

Aldgate Tube station will reopen today for the first time since the 7 July bombing.

The Metropolitan Line, which had been partly closed, will also resume a full service. Other Tube lines are still disrupted, with all services on the Circle Line remaining suspended.

FRIENDS BEWILDERED AT HAPPY-GO-LUCKY BRAZILIAN'S DEATH

FRIENDS of Jean Charles de Menezes gathered outside Scotland Yard for a peace vigil yesterday, united in their grief and bewilderment at the killing of an outgoing young man.

Just a few feet away, the presence of armed police must have been unnerving for the 30 or so Brazilians.

Waving banners proclaiming "sorry is not enough" and their national flag, the young men, women and children sang peace songs in Portuguese.

They faced a row of police officers blocking the entrance to Scotland Yard.

Nay Lemos, a former flatmate of Mr de Menezes, described him as "happy-go-lucky, a joker" from the rural, central province of Minas Gerais. "Why is it always the good ones who die young?" he asked. "I am dark, maybe people look at me and think I am a suicide bomber."

In Brazil, Mr de Menezes's parents angrily questioned why the police killed him. "I'm totally outraged with the police. How can they kill workers?" asked Mr de Menezes' mother, Maria, sobbing at home near the town of Gonzaga. "This is a pain that nothing is going to ever cure."

Mr de Menezes's father, Matzinhos, clutched a picture of his son, in which he was bare chested and working out with barbells while wearing a cap adorned with the word "London" and a Union Flag.

He said his son chose to live in Britain after obtaining a work visa, having been rejected by the US. He had warned his son that it might be dangerous living in Britain, but Mr de Menezes told relatives on his first visit back home last summer that he was happy, working hard, had friends and felt safe.

"They don't have violence," he had said, his father recalled. "It's good there, nobody walks around with a gun."

Mr de Menezes, an electrician, was not interested in politics or religion, his friends say. He was legally in the UK, with indefinite leave to remain and was expected to leave in another two to three years, when he had enough saved up to go home to buy a cattle ranch. Nobody could explain why he failed to stop on Friday.

Some doubt that he heard police warnings. There is a widespread belief he was confused because the police were not in uniform.

Mr de Menezes had a weekly travel card for the Underground so there was no need for him to jump the barrier. His decision to wear a winter coat in July did not surprise his fellow Brazilians, who pointed out that even the summer London temperatures are still cold for them in comparison.

Wagner Vieira, an ex-colleague, said the killing had made him determined to return to Brazil sooner.

"I will just make more money, more quickly, and the minute I have enough, I am leaving this country. My family don't want me to stay here any more."

GERRI PEEV