Two teenagers are in custody over the murder of journalist Lyra McKee in Londonderry on Thursday night.
Officers are using technology to work out precisely where a phone signal is coming from.
Crews from 14 fire engines are tackling the blaze, with walkers told to keep off Ilkley Moors.
And the UK is set for record-breaking temperatures over the rest of the Easter weekend.
The Met, which has requested 200 extra officers, clears Extinction Rebellion from Oxford Circus.