Two men shot by police after the horrific murder of a soldier were both known to security services.
With the suspects under armed guard in different London hospitals last night, it was understood police had also searched a Lincolnshire home formerly occupied by Michael Adebolajo.
The soldier hacked to death in Woolwich, south-east London, on Wednesday was yesterday named as father-of-one Lee Rigby.
Drummer Rigby, 25, from Crumpsall, Manchester, was from 2nd Battalion The Royal Regiment of Fusiliers, attached to the Regimental Recruiting Team in London.
Sergeant Barry Ward said he was "a loving father" to his two-year-old son Jack, and had "a very bubbly character".
Drummer Rigby, who joined the Army in 2006, had served in Helmand province, Afghanistan. He had also stood outside the Royal Palaces as part of his battalion's public duties commitment.
A total of four people, including the two men shot by police, have now been arrested in connection with the soldier's murder.
Scotland Yard said a man and a woman, both 29, were being held on suspicion of conspiracy to murder and were being questioned at a police station in south London.
The two men who were shot, aged 22 and 28, have been arrested on suspicion of murder and remain in hospital in a stable condition with non life-threatening injuries.
Six residential addresses were searched yesterday as part of the investigation – three in south London, one in east London, one in north London and one in Lincolnshire.
In a statement, Scotland Yard said: "This is a large, complex and fast-moving investigation which continues to develop.
"Many lines of inquiry are being followed and the investigation is progressing well."
Officers have recovered a number of items from the murder scene and continue to appeal for witnesses to get in touch, and send in footage and photographs of what happened.
In the immediate aftermath of the killing, video footage emerged of two men clutching bloodied weapons, including a meat cleaver.
One clip showed a man with blood stained hands claiming the killing was committed in the name of Allah and ranting about the Government.
Following a meeting of the Cobra emergency response committee on Wednesday, David Cameron said: "What happened yesterday in Woolwich has sickened us all.
"On our televisions last night and in our newspapers this morning, we have all seen images that are deeply shocking."
He said the attack was "a betrayal of Islam" and that the best approach was to "go about our normal lives".
US president Barack Obama said: "The United States stands resolute with the United Kingdom, our ally and friend, against violent extremism and terror.
"There can be absolutely no justification for such acts, and our thoughts and prayers are with the family of the victim, the police and security services responding to this horrific act and the communities they serve, and the British people."
Anjem Choudary, former leader of banned Islamic group Al Muhajiroun, said he knew one of the alleged attackers but had not seen him for about two years.
He said he recognised the man who was filmed wielding a bloodied meat cleaver.
