Live: Police search for Tube attacker - BBC News
Bringing you the latest on the search for the Parsons Green tube attacker.
The national terror alert level was raised to critical later on Friday evening, hours after Friday morning's bombing.

Asked why it took hours to increase the level, Security Minister Ben Wallace tells the BBC's Today programme:

Quote Message: The threat level in this country is set independently of politicians by the Joint Terrorist Analysis Centre. The threat level in this country is set independently of politicians by the Joint Terrorist Analysis Centre.

Quote Message: They look at a range of things. They look at the intelligence at their fingertips. They look at changes in people we are currently watching - and see if they are inspired by an attack to maybe copy things - and they look at the pace of the investigation. They look at a range of things. They look at the intelligence at their fingertips. They look at changes in people we are currently watching - and see if they are inspired by an attack to maybe copy things - and they look at the pace of the investigation.

Quote Message: If they feel as a result of all those factors that an attack is likely to become imminent then that's why they raise it to critical as they then did later in the day." If they feel as a result of all those factors that an attack is likely to become imminent then that's why they raise it to critical as they then did later in the day."