Update: bomb explodes in Derry while Army officers try and defuse it

 
Police have confirmed that a bomb has exploded outside the home of a serving police officer in Derry.
It’s understood that it happened as army technical officers were trying to defuse the bomb which was discovered earlier this morning in the Culmore area of the city.
A number of homes have been evacuated and the area has been cordoned off.
There are no further details at this stage.