People attend an award function during a hot day on the outskirts of Mumbai, India, on Sunday. Reuters

Officials said that an estimated one million spectators waited for hours in the sun at a government-sponsored awards ceremony.

Around 300 felt ill at the event near the western city of Mumbai on Sunday, when temperatures hit close to 38˚C with high levels of humidity, local media reported.

Senior government officials attended the ceremony, including Interior Minister Amit Shah, who praised the crowd for waiting so long in the sun.

The office of Maharashtra state Chief Minister Eknath Shinde described it as a "sad and disturbing incident" and promised compensation for the victims' relatives.
India's ruling Bharatiya Janata Party said around a million people attended the event, the Indian Express newspaper reported.

The opposition Congress party accused the government of negligence and said it should face criminal charges.

People gather to attend an award ceremony on the outskirts of Mumbai on Sunday. AFP

Chief Minister Eknath Shinde and others rushed to the MGM Hospital in Navi Mumbai on Sunday evening to inquire after the well-being of the people admitted there.

As the tragedy snowballed into a huge political embarrassment for the government, a grim Shinde appealed to political leaders "not to politicise" the disaster.

He also announced a compensation of Rs5,00,000 to the kin of the deceased and said the other patients are being cared for properly.

Early on Monday, NCP's leader of opposition Ajit Pawar, Shiv Sena (UBT) President and former Chief Minister Uddhav Thackeray, Congress leaders visited the hospital and interacted with the patients. "After discussing with the victims, it appears that there was a stampede as people wanted to rush out after the event," Pawar said.

Thackeray said that the function, originally scheduled for 5:00pm on Sunday, was pre-poned to morning 10:30am as Shah "had no time" and led to the loss of innocent lives.

State Congress President Nana Patole said this is the "most insensitive government" and demanded the resignation of the chief minister for the lapses leading to the tragedy.

People gather to attend an award ceremony on the outskirts of Mumbai. AFP

Chief Spokesperson Atul Londhe said that it was a government function and hence it was it's duty to ensure the safety of all the participants. "So many people have lost their lives. The government should be booked for culpable homicide and action should be taken against those responsible," demanded Londhe.

Aam Aadmi Party state President Preeti Sharma-Menon expressed shock at the huge loss of lives.

Others have questioned why the heat factor was not taken into account before organising a Rs13 crore mega-event with so many speakers, including Appasaaheb Dharmadhikari who delivered a lengthy speech while the people were visibly suffering in the raging sun.

Londhe termed as "carelessness" to organised such a massive event in the open ground without any marquee or shelter at the height of the summer season.

In fact, during his speech, Amit Shah had lauded the people for sitting patiently in the 42˚C temperatures as an example of their devotion to Appasaheb Dharmadhikari.

Heatwaves have killed more than 6,500 people in India since 2010, and last year saw record temperatures in several cities across the country.

Agencies