I just got an email from a friend, who is in London. She said that the evening television said that at least 12 besides the ones arrested and named are being held for questioning in connection with the bombing.
Apparently England's security laws allow suspects in acts like the bombings to be held up to 14 days without being arrested or charged. That way the police can wrap up the investigations on those being held.
Yes, Fox was saying there's a total of 19 arrested and they were also saying they can be held up to 14 days without being charged....very cool! (Perhaps your friend can clarify, but is the 14 days allowed for just those who are arrested on terrorist-related investigations?)