Planes, helicopters and firefighters are tackling the wildfire sweeping through Arizona that has killed 19 people and destroyed around 1,000 houses.
More top news
Some 66 people have been killed after the plane they were travelling on crashed in southern Iran.
The letter calls for an end to harassment, abuse, and impunity in a world "ripe for change".
Police say that anyone who sees Whitehouse should not approach him, but instead call them on 999 and quote incident 23 of 18 February.