At least 20 Indian farmers have died and hundreds of others have been hospitalised after inhaling poisonous pesticides while spraying crops, officials said on Monday, highlighting lax safety standards in the country.

The farmers in the western state of Maharashtra, one of India's most important agricultural regions, died after using the dangerous pesticides without wearing protective gear.

“Twenty farmers are dead and hundreds are undergoing medical treatment. Fifty are critical with damage to their eyesight,” Kishore Tewari, the spokesman for a state government task force that helps farmers in distress, told AFP.

The first death was reported in August and the number of fatalities increased throughout September, according to local news reports.

They occurred in the Yavatmal region, around 670 kilometres from the financial capital Mumbai.

Activists blame a lack of regulations covering pesticides and a failure to provide poor farmers with proper safety equipment.

Tewari said the victims had not worn boots, masks or gloves. Victims reported experiencing blurred vision and excruciating headaches, he added.

“I don't have the money to buy protective gear and we spray pesticides without any safety kits,” NDTV quoted one farmer as saying.

Last week the Bombay High Court called on the Maharashtra government to ban the sale of pesticides in the affected areas.

Yavatmal police superintendent M Rajkumar told AFP that several cases had been filed against a local agricultural centre which sells pesticides to farmers.

India has nearly 260 million farmers and farm labourers eking out a meagre living.

Their livelihoods are regularly destroyed by drought and 1,417 farmers killed themselves in Maharashtra in 2016, according to official figures.

In June the state government agreed to write off loans to farmers estimated to be worth nearly $5 billion.