The terror alert level in the UK has just been raised to the highest level - critical.
This means that an attack is believed to be imminent. It usually means the security services have specific information about a planned attack. It probably links to the bomber from this morning who has not been caught yet.
It was a home-made bomb with a timer but it failed to detonate properly. If it had worked there would have been many deaths. This makes six Islamic terrorist attacks in the UK so far this year.