Britain's intelligence services have come under pressure to explain how they let two Islamic extremists suspected of hacking a soldier to death in the streets of London slip through their net.

Both of the men, under armed guard in London hospitals after being shot by police at the scene of the attack, were previously known to the intelligence services but were reportedly assessed as not posing a deadly threat.One of the men, identified as Michael Adebolajo, 28, had attended meetings of a now-banned Islamist group and reportedly sold extremist leaflets in Woolwich, south London, where the attack took place on Wednesday.British police hope to soon question Adebolajo and the other suspect, named as 22-year-old Michael Adebowale, who are both the children of Nigerian immigrants.Adebolajo had reportedly tried to travel to Somalia to fight alongside the country's Al Shabaab insurgents but had been turned back and had his passport confiscated by police.