"Incessant rains which continued to wreck havoc over the entire state throughout the current monsoon season, have left 660 dead so far," UP's principal revenue secretary Balwinder Kumar said.

Most of the deaths have occurred due to collapse of weak houses, largely in the poor rural areas of the state. "About 2500 houses were completely devastated while more than 33000 were partially damaged, but very few of these were reported from cities," Kumar said.

Intermittent heavy downpour also led to swelling of most rivers , including the Ganga that was already flowing above the danger mark at certain places. Other Himalayan rivers including the Yamuna, Ghaghra, Rapti and Sarda were also in spate .

According to Kumar, "21 of the state's 80 districts were affected by rain and floods, that had left 674 villages marooned, and more than 1.5 million people were displaced."

Rain and floods had also caused heavy damage to standing crops � the only source of livelihood for millions living in the country's most populous state.

"The government have established several relief camps while special teams were deployed to evacuate marooned people," Kumar pointed out .

"Some ex-gratia was also being provided to those whose houses had collapsed as well as those who had suffered loss of crop or cattle," Kumar added.