Floods unleashed by days of unseasonal heavy rain have wrecked crops, blocked roads and washed away bridges in northern India, killing at least 46 people, officials said on Wednesday, as they mounted rescue efforts for those stranded.

Aerial images gave glimpses of engorged rivers and partially submerged villages in affected areas in the Himalayan state of Uttarakhand, which is especially prone to flooding, although other areas have also suffered in this week's downpours.

"There is huge loss due to the floods...