All three remaining July 21 rucksack bombers are believed to be in police custody tonight after eight days on the run.
The suspected Hackney bus bomber is among three men held after dramatic raids in West London today, while the Italian interior ministry reported tonight that it had seized the fourth bomber in Rome. They named him as Hussain Osman, a Somali-born man believed to be the Westbourne Park bomber.
The British anti-terror chief has confirmed that a man "of interest to the London bombs investigation" is being held in Rome and that a European arrest warrant has been issued seeking the return Hussain Osman to the UK
The events mean that all four men suspected of trying to blow up targets in London transport on July 21 are alive and in the hands of the authorities. Yasin Hussein Omar, the suspected Warren St Tube bomber, was shot with a stun gun and arrested in a dawn raid on a house in Birmingham on Wednesday.
To have four live suspects, plus the rucksacks which failed to explode on July 21, is likely to prove a treasure trove of information to the police.
Peter Clarke, the head of the anti-terrorist branch, confirmed tonight that a total of three men had been arrested at two addresses in London today.
In a day of high drama for the investigation, the first person to be held was arrested at an address near Tavistock Crescent, Notting Hill, after armed police and a bomb disposal unit surrounded the house. A controlled explosion was used to remove the door of the property, frightening people who lived nearby, and it is thought that a number of lesser explosions that followed may have been stun grenades.
It is understood that he did not put up a struggle. Witnesses reported seeing a man dressed in white suit later being led away by police, who were shielding his face.
Two hours later, two other men were arrested in a Peabody Buildings flat in Dalgarno Gardens, North Kensington. A second man was arrested at the same flat.
One of the men identified himself as Ibrahim Muktar Said, the suspected Hackney bus bomber, Mr Clarke said. The other was named as Ramzi Mohammed. There had been fears that a fifth bomber might be on the loose.
Both men were asked to surrender but failed to do so, forcing the police to use specialist tactics to make the arrests.
The second flat is in an area yards from the Little Wormwood Scrubs park where a fifth rucksack bomb was found discarded last week.
At about 1700 BST, the Italian interior ministry posted a statement on its official website claiming to have arrested the last remaining suspected bomber still on the run. The statement on behalf of Giuseppe Pisanu, the interior minister, said that Hussain Osman, 27, a man of Somali extraction who - like Said - was a naturalised British citizen, was picked up by Italian police in Rome a short while ago.
The statement praised the effectiveness of Italy's security services and of the international co-operation which had led to the arrest, but gave no further details.
Just after 1900 BST Mr Clarke confirmed that an arrest had been made in Rome and a warrant issued for Hussain Osman.
Sources close to the Italian investigation say that Osman was arrested in a hotel lounge close to one Rome's main railway stations, and that British security forces were involved in the arrest. They said that he left London two days ago, and had been traced by phone calls he had made to contacts in France and Italy.
Earlier, witnesses reported seeing armed police outside the only entrance to Block K of the Dalgarno Gardens housing estate run by the Peabody Trust, shouting at a suspect named as "Mohammed" and "Mr Ahmed" who was in a top floor flat, to give himself up.
"They have their guns pointed up and they have been telling him for about 20 minutes to get his clothes off and get down," said Lisa Davis, an Australian woman in a nearby flat, in a phone interview with Sky News.
"They keep assuring him that if they do what they say and come out he will be alright. It is pretty nerve-wracking."
Shortly after Ms Davies gave her account on television, the Metropolitan Police asked all broadcasters to stop airing live footage of the siege as it was entering a "challenging phase".
It is understood that police had kept at least one of the addresses under surveillance overnight, and launched major operations this morning.
One witness, Nicolas Holliman, said that he could tell there was more than one man in the Dalgarno Gardens flat by the way in which police were shouting at the property. He said there were vocal protests coming from the flat.
Another witness said one of the suspects was heard shouting ‘I’ve got rights’. After some time, Mr Holliman said heard several shots which he believed were gas being fired at the flat and then there was silence. Outside the flat there were police officers and marksmen with gas masks, as well as a helicopter overhead.
A woman living in Sutton Way, North Kensington, close to the Peabody Estate, said: "I understand a bomb went off in K block of the Peabody. They got everyone out first and no one was hurt."
The woman, who would not give her name, went on: "The whole area has been cordoned off, including Ladbroke Grove. The police activity started between 9 and 10am."
There are about 350 properties in the 24 blocks on the Dalgarno Gardens estate, which is owned by the Peabody Trust, a housing association and community regeneration agency. A spokeswoman for the Trust said that residents had been told to stay indoors while the operation was in progress.
Neighbours near Tavistock Crescent reported hearing a loud blast this morning, followed soon after by a number of smaller explosions which police reportedly said afterwards had been stun grenades. There was heavy police presence, which included an army bomb disposal team.
A man who lives in a block of flats nearby told Sky News: "The first thing I heard was what sounded like a very loud controlled explosion. A policeman told me to get to the back of the building and so I stayed in the bathroom for 15 minutes.
"Eventually I came out and heard six loud explosions that I was told were stun grenades. There were a lot of people running away down the road in panic. The noise I heard at first was an extremely loud bang, quite different from the six volleys after which weren't nearly as loud."
Meanwhile two women have been held in dramatic arrests at Liverpool Street station in the City. One woman is thought to have been in the queue for the Stansted Express train, which goes to the airport, when armed officers pinned her to the ground. Both the mainline station and the Tube station were evacuated, as were neighbouring streets.
At Liverpool St station a witness standing yards from where one woman was arrested told BBC News 24 that plainclothes police "suddenly burst into the main centre of the station and seized two women.
"They pinned them down on the floor, put their hands behind their backs, put handcuffs on them and took them away," he said.
"They’ve now evacuated the whole of Liverpool Street station and some of the streets nearby. There are now hundreds of people surrounding the station who were trying to catch a train and can’t get in."
He said: "One witness said one of the women was queuing at the Stansted Express ticket office and another said they saw a rucksack nearby on the floor, but I didn’t see that."
He said he saw plainclothes officers wearing caps which indicated they were police. "Initially there was obviously a bit of chaos. They tried to push people away and tried to stop people taking pictures with their mobile telephones. They were gradually pushing people further and further back."
Until today, police had arrested only one of the bomb suspects who tried to set off devices on three Tube trains at the Oval, Warren Street and Shepherd’s Bush and a bus in Hackney on July 21. Yasin Hassan Omar was shot with a stun gun and arrested during a dawn raid on a house in Birmingham on Wednesday.
Omar, a 24-year-old Somalian, is the prime suspect for the failed bomb attack on a Tube train near Warren Street in London.
The Metropolitan Police had issued a statement confirming that they had "conducted operations at two residential addresses in West London" in connection with the failed July 21 London bombings. The statement said: "Officers are now in the process of securing those two premises which are now being treated as crime scenes. Police have arrested two men at one address and a third man has been arrested at the second address. They are being taken to a Central London police station for further questioning."
The Italian statement said: "Congratulations to the Chief of Police (Prefect de Gennaro) and his excellent team. The arrest a short while ago in Rome of the Somali Osman Hussain, naturalised Briton, the fourth suspect from July 21 in London, deserves praise.
"The continuing anti-terrorist operation is being conducted in the context of international collaboration. It confirms not only the effectiveness of our security measures but also the efficiency of international links. It's a good sign on the day the (Italian) senate has approved - almost unanimously - a new anti-terror law. "
Italian news sources are reporting that Osman told police that he was in Rome because his brother lived there.
