India's Prime Minister Narendra Modi, who is battling to win a second term, has used his favourite medium - Twitter - to put out a pro-vote rallying cry.

Voters at one polling booth in Baraut - in the northern state of Uttar Pardesh - are in for a pleasant surprise.

They are being greeted by drums and a shower of flower petals!

If you're voting in Baghpat you better hurry or you might miss the special welcome!

Being a poll booth official in India is not an easy job!

They have a lot on their plate, from setting up booths to sorting through seemingly endless electoral rolls.

Here are some election officials in the northern state of Jammu and Kashmir busy checking the electronic voting machines before polling began.

Image source, Getty Images

The poll officials in the north-eastern state of Nagaland are carrying voting machines to polling stations. We love the colourful cloth bags!

Image source, Getty Images

In the central state of Chhattisgarh, people are queuing up to vote despite a boycott call by Maoists.

Our correspondent Salman Ravi says the Maoists have put up posters calling on people to boycott the election, and rejecting the politics of voting.

He took these pictures of people lining up.

They do so despite the fact that a lawmaker from the BJP and four of his security personnel were killed in an attack by suspected Maoists in the state on Tuesday.

A lovely graphic here to give a sense of India's massive population. Which state has as many people in it as your country?

From polling stations to counting: This is a handy animated look at the inner workings of the world's largest democracy.

India's election commission really goes the extra mile to make sure people vote.

People vote in all kinds of terrains, from bustling cities to inaccessible and sparsely populated villages. The two union territories that are voting today for instance, are archipelagos off India’s east coast.

Poll officials often trek through snow to reach remote Himalayan villages or hop on boats to reach low-lying islands in the Sunderbans.

Image source, Getty Images

And for decades, they have been going deep into the Gir forest in the western state of Gujarat just so this man can cast his vote.

Image source, Getty Images

They have also been known to use every mode of transport - from helicopters to camels - to carry poll officials and the voting machines wherever they need to go.

A small snapshot of the voting that's taking place today, across 18 states and 2 union territories.

Jammu, north India:

Andhra Pradesh, south India:

West Bengal, eastern India:

Maharashtra, western India:

The Trinamool Congress, the party in power in West Bengal, created history by ensuring that 40% of its candidates were women.

The BBC's Soutik Biswas is in the constituency of Cooch Behar in the state, which is voting today.

Voting days are also usually holidays for many in India with schools and government offices closed.

Schools are often used as polling booths - like this one in Ghaziabad in the northern state of Uttar Pradesh, pictured below.

The idea is also that a day off from work will encourage more people to turn up and vote!

Image source, Getty Images

The BBC's Rajini Vaidyanathan explains why this election matters.

Our correspondent Rajini Vaidyanathan met India's oldest voter, who is 102!

Shyam Saran Negi is a retired school teacher and he has voted in every Indian election since 1952.

He lives in the northern state of Himachal Pradesh, which will go to polls on 19 May.

And of course, he plans to vote this time too!

Our correspondent Salman Ravi is in the central state of Chhattisgarh, where voting is taking place for one of its 11 seats.

Polling is going to close early - at 3pm - after a lawmaker from the governing Bharatiya Janata Party (BJP) and four of his security personnel were killed in an attack by suspected Maoists on Tuesday.

The mineral-rich state has witnessed an armed conflict for more than three decades and attacks by Maoist rebels on security forces are common.

Some polling booths have been moved away from sensitive areas and additional security forces have been deployed - 80,000 officers according to some news reports.

Here is what our correspondent is tweeting:

Today is just the beginning of a marathon polling period. This is one of the longest elections in the world!

Indians will vote on seven different days between 11 April and 19 May. And all these votes will be counted on the same day - 23 May.

In many states, different constituencies will go to the polls on different days. So some states, like Bihar and West Bengal, will see their election staggered over several weeks, in different stages - or "phases" as they are called in India.

In others however, it’s all over in a day. Ten of the states and union territories who are going to the polls today will see their polling end.

If you're interested to know which states vote when, you can read more about it here.

If 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:

Hello, and welcome to the BBC’s live coverage of the first day of voting in India.

Over the next six weeks, voters from across the country will take part in the largest election the world has ever seen.

It’s 07:00 local time in India’s capital Delhi and polling booths have just opened.

Today, 142 million people are eligible to vote in 170,664 poll booths across 18 states and two union territories.

So we can expect to see long long lines like this:

Image source, Getty Images

We will be bringing you regular updates from our correspondents across the country. Stay tuned!