STOCKHOLM A Middle Eastern man killed in a blast in Stockholm was wearing a bomb belt and ready to attack a train station or department store when the device went off prematurely, Sweden's chief prosecutor said on Monday.
Police were all but certain the attacker was Taymour Abdulwahab, who emigrated to Sweden in 1992 but mostly lived in Britain with his wife and two children.
A militant who first identified Abdulwahab in an online message that included his photograph on Sunday issued a new statement on Monday warning of more such attacks if Western troops did not withdraw from Afghanistan.
"The battle of Stockholm is the start of a new era in our jihad, when Europe will become the arena for our battles," the Arabic-language message said, according to a translation by Flashpoint Partners, a U.S.-based service that tracks publications by militant groups.
The message, also monitored by another Islamist militant monitoring service, the Site Intelligence Group, added: "Those who insist on not heeding our demands must expect our attacks, which will reach the heart of Europe."
There was no way of independently confirming that the speaker had links to Abdulwahab but intelligence services were expected to study it for clues about ties to a militant network.
If he was, such a group could be plotting other bombings.
Interviews with people who knew him painted a portrait of a bubbly, fun-loving man who became increasingly radical in his views in Britain, and fell out with a local mosque there in 2007 over his extreme political opinions.
The attack, the first of its kind in Sweden, has heightened fears about attacks in Europe during the Christmas holidays.
The incident began when a car containing gas cylinders blew up in a shopping area in central Stockholm on Saturday. Minutes later a blast nearby killed the bomber and hurt two people.
"He was wearing a bomb belt and was carrying a backpack with a bomb," chief prosecutor Tomas Lindstrand told reporters.
"He was also carrying an object that looks something like a pressure cooker. If it had all exploded at the same time, it could have caused very serious damage," he said.
"It is not a very wild guess that he was headed to some place where there were as many people as possible, perhaps the central station, perhaps Ahlens (a department store)."
Lindstrand said the man was almost certainly Abdulwahab, who has been widely named in media, and that he assumed there had been accomplices, as the attack was well planned.
Justice Minister Beatrice Ask said the U.S. Federal Bureau of Investigation had sent seven bomb experts to help in the enquiry, the TT news agency said.
Lindstrand said Abdulwahab came from a Middle Eastern country, although it was unclear which. An entry by Abdulwahab on a Muslim dating website gave his birthplace as Iraq.
The Swedish immigration service said he had come to Sweden in 1992 and got citizenship six years later.
He studied at a university in the southern English town of Luton and graduated in sports therapy in 2004.
Luton is home to a large Muslim community, and was the place where the suicide bombers behind a deadly July 2005 attack on London's transport system met to begin their operation.
Police searched the house in Luton where Abdulwahab lived with his wife and children. Swedish officials said he had traveled periodically to a home in the town of Tranas, 200 km (120 miles) southwest of Stockholm, which was also searched.
"He has some relatives in Sweden and he also, what I know, has another life in England," Swedish Security Police Director of Operations Anders Thornberg told Reuters Television.
Shortly before the blasts, the Swedish news agency TT received a threatening email with an attached sound recording criticizing Sweden's deployment of troops in the NATO-led force in Afghanistan, as well as caricatures of the Prophet Mohammad by a Swedish artist that angered Muslims in 2007.
"To all Muslims in Sweden I say: stop fawning and humiliating yourselves, for a life of humiliation is far from Islam. Help your brothers and sisters and do not fear anything or anyone, only the God you worship," the email said.
Swedish newspapers had video clips of the blast that killed Abdulwahab and the immediate aftermath.
In one, on the website of Aftonbladet, people go up to the man and pull off a blanket and sheet that have been placed over him. "He is alive, he is alive," says a woman, before being urged to move away because of other bomb parts lying nearby.
Farasat Latif, secretary of the Luton Islamic Center Mosque, said Abdulwahab had worshipped there in 2007.
"He was very friendly, bubbly initially, and people liked him. But he came to the attention of our committee for preaching extremist ideas," Latif told Reuters. When confronted, Abdulwahab stormed out and was not seen again at the mosque.
In his home town in Sweden, residents also described an outwardly fun-loving person. "He was very handsome and outgoing. No one would dream he could do something like this," said one woman who knew him in his teens. "I am absolutely devastated."
Swedish officials said Abdulwahab had never come to their attention before.
Though Sweden has never had such an attack, the Security Police have acted over the years to stop people traveling from Sweden to conflict zones, particularly Somalia.
A court on Friday jailed two men linked to the al Shabaab militants for 4 years for conspiracy to commit a terrorist act.
(Additional reporting by Isabel Coles in Luton, Stefano Ambrogi in London, Mia Shanley in Tranas, Ilze Filks and Johann Sennero in Stockholm; Editing by Jon Hemming)