The Icelandic Road and Coastal Administration has closed roads and banned hiking in a large area north of the Bardarbunga volcano.
The black hatched area on the map below shows the region that is out of bounds:
The organisation warns of a "danger of flooding in connection with a possible volcano eruption".
More top news
Ms Leadsom has received the backing of Ian Duncan Smith, the former work and pensions secretary.
The former shadow work and pensions secretary is considered a more viable candidate than Angela Eagle, a Labour source has told ITV News.
Between eight and 10 people have been rescued following the raid, according to Bangladeshi police.