MUMBAI, July 4 — Thirteen bodies have been recovered in western India after the heaviest monsoon rains in a decade breached a dam and caused mayhem in Mumbai, authorities said today.

Eleven people were still missing after the dam in Ratnagiri, around 275 kilometres south of Mumbai, burst yesterday and swamped seven local villages, rescuers said.

"We have commenced rescue operations for the second day and recovered 13 dead bodies. We are still trying to find remaining victims,” National Disaster Response Force spokesman Alok Awasthy told AFP.

In Mumbai, the death toll from a wall collapse in a slum on Tuesday rose to 26 as the city braced for 200 millimetres of fresh rain forecast in the coming days.

Six labourers also died in the nearby city of Pune when another wall collapsed on Tuesday.

Building collapses and dam breaches are common during the monsoon in India due to dilapidated structures that buckle under the weight of continuous rain.

Torrential downpours in Mumbai — a city of 20 million — earlier this week caused traffic misery as floods swamped roads and railways and forced the closure of the airport's main runway, which remained off limits today.

India's second-busiest airport cancelled 75 flights yesterday and more than 100 on Tuesday, causing chaos for passengers. — AFP