Scotland Yard is set to question the second suspect shot at the scene of last week's terror attack which resulted in the murder of soldier Drummer Lee Rigby in south-east London.
Michael Adebolajo, 28, spent his second day in custody at a London police station on Saturday after being discharged from hospital on Friday.
He is also being held on suspicion of attempting to murder a police officer in relation to the attack in Woolwich on May 22.
His suspected accomplice, 22-year-old Michael Adebowale, has been charged with the soldier's murder and appeared before Westminster magistrates on Thursday.
Both Londoners of Nigerian descent, believed to be Islamist extremists, were shot and arrested at the scene of the killing and were being held under police guard at different London hospitals.
Adebowale had been discharged earlier this week and is due to appear in court again on Monday.
Police investigating the Woolwich attack have also arrested a 42-year-old man in North London and a 46-year-old man in East London on suspicion of involvement in the supply of illegal firearms.
The total number of arrests made in connection with the attack stands at 12.
So far, six of those arrested have been bailed and two released without charge.
A far-right British National Party (BNP) march is expected in Westminster later after police asked that it be moved from Woolwich.
Faith Matters, an inter-faith organisation aimed at tackling extremism, said it had recorded 212 Islamophobic incidents since last Wednesday, up from between four and six per day.
In a statement, Lee Rigby's family stressed that "Lee would not want people to use his name as an excuse to carry out attacks against others."
Queen Elizabeth II also paid her respects to the fallen soldier during a royal visit to the barracks on Friday.