LONDON — A man seen with bloody hands wielding a butcher knife after the killing of a British soldier in London was described as a convert to Islam who took part in demonstrations with a banned radical group, two Muslim hard-liners said Thursday.
Police raided houses in connection with the slaying of the off-duty soldier, identified as Lee Rigby, of the Second Battalion of the Royal Regiment of Fusiliers, who served in Afghanistan. In addition to the two suspects who were hospitalized after being shot by police, authorities said they had arrested a man and a woman, both 29, on suspicion of conspiracy to murder.
Police would not say whether it appeared Rigby had been targeted because of his military service. Although he was not in uniform at the time he was killed, he was said by witnesses to be wearing a T-shirt for a British veterans’ charity.
Authorities have not identified either of the two wounded suspects and have not said when they would do so. Officials in Britain usually wait to name suspects until charges have been filed.
Anjem Choudary, the former head of the radical group al-Muhajiroun, said that the man depicted in a startling video that emerged after Rigby’s death was named Michael Adebolajo, a Christian who converted to Islam around 2003 and took part in several demonstrations by the group in London.
The BBC broadcast video from 2007 showing Adebolajo standing near Choudary at a rally.
Omar Bakri Muhammad, who now lives in Lebanon but had been a radical Muslim preacher in London, also said he recognized the man seen on TV as Adebolajo and said he attended his London lectures in the early 2000s.
Bakri, speaking from Lebanon, said he remembers Adebolajo as a ‘‘shy person’’ who was keen to learn about Islam.
The two men suspected of killing Rigby, 25, had been part of previous investigations by security services, a British official said Thursday, as investigators searched several locations and tried to determine whether the men were part of a wider terrorist plot.
Rigby, the father of a 2-year-old boy, was slain Wednesday afternoon outside the Royal Artillery Barracks in the Woolwich area of south London while horrified bystanders watched.
The bizarre scene was recorded on witnesses’ cellphones, with one of the two suspects boasting of their exploits and warning of more violence as Rigby lay on the ground. Holding bloody knives and a meat cleaver, they waited for the arrival of police, who shot them in the legs, according to a passerby who tried to save the dying man.
A British government official said one of the two men tried to go to Somalia to train or fight with the terror group al-Shabab. The official, who spoke on condition of anonymity because he was not authorized to speak about the police investigation, would not say if the suspect had been arrested or whether he had made any other trips to the country.
Prime Minister David Cameron vowed that Britain would not be cowed by the horrific bloodshed, and that it would reject ‘‘the poisonous narrative of extremism on which this violence feeds.’’ In Washington, President Obama said the United States ‘‘stands resolute with the United Kingdom’’ in the fight against violent extremism.
Dramatic video showed a black man — hands stained with blood and holding a meat cleaver — criticizing the British government and the presence of UK troops in foreign lands.