Indian residents wade through flood waters in Visakhapatnam in the coastal district of Andhra Pradesh on November 5, 2012.

Story highlights

About 70,000 people are in temporary shelters because of the floods

Heavy rain from a tropical storm overwhelmed the water system

The flooding has killed 25 people in the state of Andhra Pradesh

It has also affected thousands of square kilometers of crops

New Delhi CNN  — 

Flooding in southern India in the wake of a tropical cyclone has killed 25 people in the past few days and driven tens of thousands of others from their homes, authorities said Tuesday.

The severe weather has caused flooding affecting 5,250 square kilometers (2,000 square miles) of agricultural land in the state of Andhra Pradesh, according to Vinod Kumar, an official at the state’s disaster management department.

Cyclone Nilam roared into India’s southeastern coast last week, killing at least 15 people in the state of Tamil Nadu and running a large oil tanker aground on the shore near Chennai.

The storm had already been drenching coastal areas with rain as it loitered over the sea north of Sri Lanka before it made landfall. It brought more than a month’s rainfall in just a few of days, according to CNN meteorologist Ivan Cabrera.

The “high impact, long duration” nature of the downpours “overwhelmed the rivers and streams” and led to the disastrous flooding, Cabrera said.

About 70,000 people in Andhra Pradesh, which is north of Tamil Nadu, have been relocated to temporary shelters, Kumar said Tuesday. The flooding has killed 25 people in the state, he said.

The full extent of the damage to crops won’t be known until after the flood waters recede, according to authorities.

Tropical cyclones tend to occur in the Bay of Bengal and the Arabian Sea during the April-to-June and September-to-November periods.

A violent tropical storm killed at least 23 people in southeastern Bangladesh last month. And a powerful cyclone that hit India and Bangladesh in May 2009 killed at least 180 people.

CNN’s Jethro Mullen in Hong Kong contributed to this report.