Lots of voters are telling BBC correspondents at polling booths that they want one key thing: more jobs.

Although annual GDP growth has hovered at around 7% under Mr Modi's government, not enough jobs have been created for the country's burgeoning young population.

Mr Modi's government has also been accused of hiding uncomfortable data. In fact, a leaked government report suggests that the unemployment rate is the highest it has been since the 1970s.

He came to power promising to reinvent India as a technological and economic powerhouse. But even though the government has invested heavily in infrastructure, economic growth hasn't met expectations and the farming sector has stagnated.

Read more about what is at stake for Mr Modi here.

India's 170 million Muslims, many say, have become an "invisible" minority.

The BJP has no Muslim MPs in the lower house - it fielded seven candidates in 2014 but all of them lost.

The party's landslide win in 2014 led many to wonder if it was in fact a vote for its strident Hindu nationalism.

There have been numerous instances of Muslims being harassed or attacked in the past five years, often because of rumours of cow smuggling.

While some hold the BJP's brand of Hindu right-wing politics responsible, others say India has always been a divided country.

We asked some of them what was on their minds as they voted:

Well they do, and here it is:

Narendra Modi won a landslide victory on a platform of Hindu nationalism and bold economic promises.

But while Mr Modi led the BJP to its greatest victory, his main opponent Rahul Gandhi was the face of Congress when it suffered its worst ever defeat.

Sanjay Savarkar is getting married today.

But before the nuptials, he stopped by his polling booth in Wardha district of the western state of Maharashtra.

He also kindly agreed to pose for our colleagues from BBC News Marathi.

India's election is a huge logistical challenge - getting hundreds of millions of people across a vast country to cast their ballot is no easy feat.

So how does the voting and counting process actually work?

This photograph was taken by our correspondent Salman Ravi in the central state of Chhattisgarh. It shows a polling booth in Kilepal, in restive Dantewada district.

Salman says only two votes have been cast there in five hours. The writing on the wall in red is a message from Maoist rebels demanding that people boycott the election.

Other parts of the district have, however, seen brisk voting.

Chhattisgarh has witnessed an armed conflict for more than three decades and attacks by Maoist rebels on security forces are common.

A lawmaker from the BJP and four of his security personnel were killed in an attack by suspected Maoists on Tuesday.

The Maoists, who are active in several Indian states, say they are fighting for communist rule and greater rights for tribal people and the rural poor.

One person has died after clashes between supporters of the two main political parties in the southern sate of Andhra Pradesh.

Our reporters from BBC Telugu say that the two factions - from the ruling Telugu Desam Party (TDP) and the YSR Congress - attacked each other near a polling booth in the state's Anantpur district.

Four others are critically injured, our reporters say.

Other clashes have been reported in the state's Guntur district.

All 25 seats of the state are going to polls today.

This woman - Shobhana Kamineni - cut short a holiday abroad to come back to India and vote.

But when she arrived at a polling station in the southern state of Telangana her name was missing from the voter list.

She spoke to BBC News Telugu about her anger and disappointment.

Ms Kamineni's brother-in-law is a member of parliament from Telangana.

Our correspondents have been speaking to voters across the country, asking them what is at the top of their mind as they head to the polling booth.

And we got an interesting mix of answers...

In November 2016, the Indian government cancelled all 500 ($7; £5.5) rupee and 1,000 rupee notes in a shocking move in a country that still largely relies on cash.

"Demonetisation", as it was called, effectively wiped out 86% of the currency in circulation.

And it continues to haunt voters like this man in Nagpur in the western state of Maharashtra.

Mr Modi's government said the controversial policy was needed to crack down on undeclared wealth or "black money". But economists have dubbed it an "epic failure".

Those who earn almost entirely in cash were hit the hardest - small traders, farmers, domestic workers and daily wage labourers.

The humble cow, which is considered sacred by Hindus, has become a polarising animal during Mr Modi's time as prime minister.

This is especially true in states like Uttar Pradesh, part of India's agricultural heartland.

Image source, Getty Images

In 2015, a Muslim man was dragged outside his home in rural Uttar Pradesh and lynched over rumours that his family had slaughtered a cow and eaten beef. In the years since, Hindu vigilantes have lynched many Muslims over similar rumours.

Many blame Mr Modi and the BJP for enabling a muscular form of Hindu nationalism that leads to attacks on minorities.

The Congress opposition party has accused the prime minister of spreading "hate".

If you want read more about this, here's an explainer on India's cow politics.

If you're just joining us and you want to understand what’s going on - like who’s competing and the key issues at stake, here’s a really simple guide.

And if you want something a bit more in depth, try this explainer by our India correspondent Soutik Biswas.

And here's a handy graphic guide to the immense scale of this whole exercise.

There are reports of clashes taking place in Cooch Behar, one of the two constituencies where voting is taking place in the eastern Indian state of West Bengal (home to Kolkata).

The BJP party which runs India's federal government is accusing the state's ruling Trinamool Congress (TMC) of attacking its supporters, a charge they are denying.

We are awaiting further details.

This year, for the first time ever, more women are expected to vote in India than men. And we are seeing evidence of that from across the country.

Voting has been underway for just under five hours.

The data below is from the Press Information Bureau of India and shows how many people have already cast their vote in the states going to the polls today.

Narendra Modi's main rival is Congress party leader Rahul Gandhi. If he becomes prime minister, the 48-year-old will be the fourth member of the Nehru-Gandhi family to hold the office.

Mr Gandhi was the face of Congress when India’s oldest political party suffered its worst defeat in 2014.

Image source, Getty Images

The fact that his father, grandmother and great-grandfather have all been prime minister motivates his supporters but also alienates voters tired of his family's grip on Indian politics.

But Mr Gandhi is not the only contender for the top job apart from Mr Modi. If Congress fails to muster a majority, it could try to pull together a coalition. To do so would mean relying on key regional politicians who could turn kingmakers.

India’s 68-year-old prime minister Narenda Modi is at the centre of this election.

Many see it as a referendum on his leadership - which has divided India.

He led his Bharatiya Janata Party (BJP) to a comprehensive win in 2014 and is hoping to repeat that performance this time around.

But they are up against powerful regional parties and a resurgent Congress, the main opposition party.

Image source, Reuters

Despite a patchy record on his 2014 campaign promises, there is no doubt that Mr Modi remains the BJP’s main vote-getter, says our correspondent Soutik Biswas.

But he is a polarising figure. While his supporters hail him as a “strongman” who leads India with the decisiveness it needs, his critics accuse him of being a Hindu nationalist hardliner who has done little to protect minorities.

If you want to understand why he is seen as divisive, read our correspondent’s deep dive into ‘Modi’s India'.

This polling booth in the union territory of Andaman and Nicobar Islands has been decorated with some festive touches.

The Andaman and Nicobar Islands are made up of more than 500 islands, but only 37 are inhabited.

At the time of the 2011 census, the population of the islands was 379,944.

The islands are home to the endangered Sentinelese tribe, who were most recently in the news for killing an American missionary with bows and arrows after he arrived on North Sentinel island.