Flags were flying at half-mast at the Houses of Parliament following a terror attack on Wednesday in which four people were killed .
The flag at the Scotland Yard headquarters was also flying at half-mast after police officer PC Keith Palmer died in the attack .
Other countries around the world showed their solidarity with the UK. In Paris, the lights on the Eiffel Tower went out as a mark of respect. In Israel, the Union Jack was projected on the municipality building.
A candlelight vigil is scheduled in Trafalgar Square in London on Thursday afternoon to mourn the victims of the attack.
Produced by Claudia Romeo
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