Polling in the fifth phase of India's mega-election was held on Monday as polls were cast in 51 constituencies across seven states, including Uttar Pradesh ─ India's biggest state which accounts for 80 of the 543 lawmakers decided in the election.

More than 87 million people across seven states were eligible to vote today. The seven-phase election began on April 11. The last votes will be cast on May 19 and results will be declared by May 23.

According to The Hindustan Times, the latest round of elections saw some high-profile contests: "Rae Bareli —where Sonia Gandhi is in the fray, Lucknow — Rajnath Singh is contesting from here, Amethi — Rahul Gandhi’s seat and Saran — where [Bharatiya Janata Party's] (BJP) Rajiv Pratap Rudy is contesting."

Amethi, the family borough of India's main opposition leader Rahul Gandhi in Uttar Pradesh, also voted today.

Gandhi, who has focused on attacking Modi's economic policies, is seeking to become the fourth member of his family to take the prime minister's office. He has pledged to end abject poverty by 2030 and give cash transfers to 50 million families.

On Friday, Gandhi penned an emotional letter to the people of Amethi seeking support for his bid for a fourth straight term from the city, amid accusations that BJP supporters were giving cash handouts to voters.

"Vote in large numbers to bring back this member of the family," Gandhi, 48, wrote.

The BJP put up a minister and former television actress Smriti Irani against Gandhi.

In 2014, the BJP decimated Gandhi's Congress party, clinching 282 seats in the biggest landslide in decades. This election is predicted to be closer.

Modi has been on a campaign frenzy across the country, portraying himself as as a strongman leader. He has capitalised on nationalist fervour, drawing complaints from rivals that he uses hate speech and the armed forces for propaganda.

On Saturday, India's poll watchdog dismissed a complaint that Modi had boasted about India unleashing missiles on Pakistan during a recent tense standoff.

Uttar Pradesh is also where Hindu nationalist groups have aggressively pushed for the building of a temple on the ruins of a 16th century mosque, in the city of Ayodhya, which has become a flashpoint in tension with minority Muslims.

The main issues here are the temple, nationalism and the countrys economic development, said Sharad Sharma, an Ayodhya-based spokesman for the Vishwa Hindu Parishad, or the World Hindu Council, a group linked to Modi's Hindu nationalist BJP.

Ahead of the polls, on Sunday, unidentified assailants shot dead a local leader of Prime Minister Narendra Modi's ruling party in Indian-occupied Kashmir, highlighting bloodshed that has marred India's mega-election.