The heaviest rains said to fall on Kashmir in 50 years caught Indian and Pakistani authorities off guard, with criticism of their disaster preparedness growing on Tuesday as the number of dead hit 420 and thousands remained trapped on rooftops.

On the Indian side of the heavily militarized de facto border that divides the Himalayan region, more than 2,000 villages and the city of Srinagar were submerged.

A senior official of National Disaster Response Force said in New Delhi, that “the damage is shocking, people have been stranded on rooftops of their homes for the last three days in some parts of Kashmir.” The official, who requested anonymity, said he would have deployed disaster response teams in Kashmir before the floods if his office had been given accurate weather predictions.

He said, “we were all caught off guard because there was not a single warning issued by the weather office. The flash floods took us by surprise.”

India’s metrological department forecast heavy rains in Kashmir last week, but the Central Water Commission, which issues flood advisories, has been criticized by Indian media for not warning the state.

A massive rescue operation led by the military was under way in both countries. Some 22,000 people have been evacuated from their homes in India, where 217 have so far been reported dead.

The flooding is the first major humanitarian emergency under new Indian Prime Minister Narendra Modi, who called it a “national disaster”. It comes at a difficult time for Pakistani Prime Minister Nawaz Sharif, who has faced weeks of street protests aimed at forcing his resignation.