Four houses in east London were raided by counter-terror detectives as part of the investigation.

Scotland Yard said a small container was removed at one of the addresses.

The container is being examined. Explosives officers attended as a precaution, although the container is now not thought to have had explosives or hazardous material in it.

A police officer can arrest anyone they "reasonably suspect" of being a terrorist, under Section 41 of the Terrorism Act 2000.

What do you reckon, attempt at quick retribution for Osama's death or a knee-jerk response from security forces on higher alert?

The arrests weren't Intelligence led and they weren't linked to or had possession of anything terroristy...

Arresting under the Terrorism Act is basically Carte Blanche to just arrest when you feel like it. Mind you, that is going by what information there is at the moment.

This was the same law that lead to the arrest of a lot of photographers.

They said they stopped the car they were travelling in as "they appeared to be taking photographs and acting suspiciously". But it emerged that they had taken a wrong turn.

Surprise. All released without charge clicky.

The men told police they were travelling along the road only because their in-car satellite navigation system had taken them the wrong way on the remote road just off the coast of Cumbria, close to the Lake District.