NEW DELHI: Tens of millions of Indians joined nationwide queues 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 reforms.

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

On the ground, security forces were on high alert and three members of rival regional parties were killed in clashes outside polling stations in the southern state of Andhra Pradesh.

Supreme Leader

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

The BJP has put Modi left, right and centre of its campaign to secure a second five-year term.

“Each (BJP) candidate contesting across India represents a miniature version of Modi. We are fighting not with our name. We are fighting with the name of our Supreme Leader, Narendra Modi,” national party spokesman Sambit Patra said ahead of voting.

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

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.