Heatwave conditions continue to sweep India where more than 1,100 people have died in the past week, officials say.

Although temperatures have marginally fallen in the worst-hit states of Telangana and Andhra Pradesh, they continue to hover around 45C (113F).

But clouds have formed over some parts of the two states and weather officials say pre-monsoon showers are likely to provide some relief in the coming days.

At least 24 people have died from the heat in West Bengal and Orissa too.

Heatwave conditions have also been prevailing in large parts of India, including in Uttar Pradesh, Jharkhand, Orissa, Rajasthan and the capital, Delhi, with temperatures nearing 50C (122F) in some areas in the past week.

Hospitals have been put on alert to treat heatstroke patients and authorities have advised people to stay indoors.

Officials say the majority of the victims are people who have been exposed to the sun directly, usually aged 50 and above and from the working classes.

Most of the heat-related deaths in the last week have taken place in Andhra Pradesh where 852 people have died and in Telangana where the toll is 266.

More than 800 people have died in the worst-hit state of Andhra Pradesh. Photo: AFP

"Heatwave conditions continue to prevail in Telangana and Andhra Pradesh. In Telangana, temperatures range from 42 to 45C. In Andhra Pradesh, temperatures continue to remain steady and the heatwave continues. The temperatures should return to normal by the week end," YK Reddy, meteorological department official in Hyderabad - the joint capital of the two states - told BBC Hindi.

Meanwhile, the authorities were advising people not to venture outside without a cap and to drink plenty of water and keep hydrated.

In Andhra Pradesh, the authorities were recommending setting up of emergency drinking water camps.

The capital, Delhi, too is enduring a week of sweltering heat as the maximum temperature in the city hit a two-year high of 45.5C (113.9F) on Monday. Tuesday wasn't much better at 45C.

Meteorological officials say the heatwave is due to a lack of rain and there are fears that some of the worst-affected states could be hit by drought before the monsoon rains arrive.

The monsoon is expected to hit the southern state of Kerala towards the end of this month before sweeping across the country.

What is a heatwave?

- Heatwaves are defined as periods of abnormally high temperatures and usually occur between March and June in India

- May is the country's hottest month, with thermometers reaching a maximum of 41C (104F) in Delhi

- Longer, more severe heatwaves are becomingly increasingly frequent globally

- Intense heat can cause cramps, exhaustion and heat stroke

- Thousands of people died across India during heatwaves in 2002 and 2003

- In 2010 around 300 people were killed by intense temperatures, according to media reports from the time