TENS of millions of Indians joined nationwide queues on Thursday to give their verdict on nationalist prime minister Narendra Modi as the world’s biggest election started amid deadly clashes.

Election officials reported a heavy turnout across the 20 states taking part in the first day of the massive exercise which involves 900 million eligible voters and will take nearly six weeks to complete.

While the 68-year-old Modi remains popular because of his tough stance on national security, he is under pressure over unemployment and controversial economic measures.

Insults and fake news have surged on social media in the run-up to the poll as Modi’s right wing Bharatiya Janatha Party (BJP) and the opposition Congress party stake their claims.

On the ground, security forces were on high alert and two members of regional parties were killed in clashes outside a polling station in Tadipatri, Andhras Pradesh state, media said.

After five people, including a local lawmaker, were killed by a roadside bomb planted by suspected Maoist rebels on Tuesday, the insurgents were blamed for two voting day blasts in Chhatisgarh and Maharashtra states.

Tens of thousands of armed police, paramilitaries and troops guarded polling stations in Jammu and Kashmir which is in the grip of an insurrection that took India to the verge of a new war with neighbouring Pakistan less than two months ago.

Thousands of parties and candidates are running for office in the seven separate days of voting in 543 constituencies up to May 19. Final results will be released on May 23.

Some 1.1 million electronic voting machines are being taken around the country for the votes, with some transported through jungles and carried up mountains, including to a hamlet near the Chinese border with just one voter.

Some 142 million people were eligible for the first day of voting.

Polling stations in northeastern states like Arunachal Pradesh bordering China were the first to open, followed by parts of Bihar in the north.

In Assam in the northeast, queues started forming well before voting began, including many of the 84 million first-time voters who could play a decisive role in the outcome.

“It’s a great feeling to cast the vote, which makes me a part of the democratic system and makes me responsible for electing a good leader,” Anurag Baruah, 23, said.

Modi appealed in a tweet to his 46.8 million followers to “turn out in record numbers.

He swept to power in 2014 with the biggest landslide in 30 years.

Critics, however, accuse him of imposing a Hindu agenda, emboldening attacks on Muslims and low-caste Dalits, re-writing school textbooks and re-naming cities.

Modi has simplified the tax code and made doing business easier, but some promises have fallen short. Thousands of indebted farmers have committed suicide in recent years.

Growth in Asia’s third-biggest economy has been too slow to provide jobs for the roughly one million Indians entering the labour market each month.

Rahul Gandhi, leader of the opposition Congress party and the latest in his family dynasty hoping to become prime minister, has accused Modi of causing a “national disaster”.