Torrential rains have swamped parts of India's tech capital Bengaluru, killing at least one person, an official said, and exposing long-standing infrastructure failures in a city that has expanded at breakneck speed.

Rapid growth of the southern city dubbed India's ‘Silicon Valley’ has left many waterways covered over or used as dumps, leading to water stagnating every year during heavy rains.

"Storm water drains are encroached upon, the drains are shallow and small, and they are filled with silt," chief minister of Karnataka state Siddaramaiah said late Monday.

"Instructions have been given to the municipal corporation multiple times to clear them, and work is still ongoing," he added.

Siddaramaiah said it was a "matter of sorrow that a woman lost her life" in Bengaluru, the state capital which is home to more than 10 million people.

The Times of India newspaper reported Tuesday at least three people had died.

India is hit by torrential rains and flash floods each year during the monsoon season, and experts say climate crisis is increasing their frequency and severity.