The Metropolitan Police said a man and a woman, both aged 29, were arrested by Counter Terrorism Command detectives on suspicion of conspiracy to murder. Police had searched five houses in London and one in Lincoln, 120 miles north-east of the capital.
Searches were ongoing and police were carrying out “a large, complex and fast-moving investigation which continues to develop.”
The two Britons of Nigerian descent, who were shot and wounded by police at the scene of their gruesome attack in Woolwich on Wednesday, are under arrest in hospital. They are aged 22 and 29.
Government sources told British media the attackers had been flagged by the domestic security service, MI5, several years ago but were assessed not to pose a terror threat.
Prime Minister David Cameron declined to comment on the claims but said investigations would review the actions of police and intelligence agencies in the run-up to the attack.
“The point that the two suspects in this horrific attack were known to the security services has been widely reported,” he told reporters outside 10 Downing Street. “You would not expect me to comment on this when a criminal investigation is ongoing but what I can say is this, as is the normal practice in these sorts of cases the Independent Police Complaints Commission will be able to review the actions of the police and the Intelligence and Security Committee [a parliamentary oversight body] will be able to do the same for the wider agencies.”
After the last Islamist terror attack in London, the deadly July 2005 train and bus bombings, MI5 was criticized for failing to prevent the attack after it was learned that it had dropped surveillance on two of the suicide bombers a year earlier because they were viewed as peripheral to a separate terror plot being investigated and it could not justify diverting resources.
Procedures were reviewed and changes made, and MI5 has been credited with foiled a number of serious terror plots over the ensuing years.
One of the two men arrested in Woolwich has been named as Michael Adebolajo, a British-born convert to Islam. He is the man who was filmed after the attack, carrying bloodied knives and railing against the British government.
“By Allah, we swear by almighty Allah we will never stop fighting you until you leave us alone,” he said on camera. “Tell them to bring our troops back so we can, so you can all live in peace.”
The attackers stayed on the scene of the killing, evidently relishing the attention and making no attempt to leave before police arrived.
The father of a two year-old old was not in uniform at the time of the attack, but was wearing a T-shirt promoting a charity for wounded veterans.
The charity, Help for Heroes, reported a surge of website traffic and donations after the attack.
Speaking in Downing Street, Cameron said the attack was not just directed at “our British way of life.”
“It was also a betrayal of Islam – and of the Muslim communities who give so much to our country,” he said. “There is nothing in Islam that justifies this truly dreadful act.”
The Muslim Council of Britain condemned the attack, calling it “a truly barbaric act that has no basis in Islam.”
“We call on all our communities, Muslim and non-Muslim, to come together in solidarity to ensure the forces of hatred do not prevail,” said the council, an umbrella group of organizations, charities and mosques.
Choudary, who describes himself as a lecturer in shari’a, ran a group called al-Muhajiroun (“The Emigrants”) along with a Syrian-born cleric and U.K. Shari’a Court “judge,” Omar Bakri Mohammed. It was banned, and Bakri was barred from Britain after the 2005 London bombings for his vocal support for jihad.
Since then, Choudary has been associated with various radical organizations – essentially the same organization with different names – including al-Ghurabaa (“The Strangers”), the Savior Sect, Islam4UK and Muslims Against Crusades.
The British government banned al-Ghurabaa and the Savior Sect in 2006, Islam4UK in 2010 and Muslims Against Crusades in 2011.