India and Pakistan will grind to a halt Saturday as hundreds of millions of cricket fans gather to watch the World Twenty20 match between the two arch-rival nations in Kolkata.

The cricket-mad neighbours, who have gone to war three times since independence, share one of the world's fiercest sporting rivalries and their rare showdowns on the pitch can bring both to a standstill.

Tensions have prevented the two sides from playing each other in Tests for more than a decade, and the match is only happening because the T20 is an International Cricket Council (ICC) tournament.

In the eastern city of Kolkata in West Bengal, thousands of security personnel deployed outside Eden Gardens stadium testified to the enormity of the encounter.

Policemen battled to keep the fans from sneaking into the iconic stadium in order to catch a glimpse of their favourite stars during practice sessions.

‘It's hard to control the crowd at times. They are all eager to get in and watch some action. Sometimes we even have to use some force,’ police constable Sudhir Ray told AFP.

Fans said they were nervous about predicting the outcome of the match.

‘You never know in an India-Pakistan game. We will always want India to win but Pakistan are looking dangerous,’ said Mannu, a tea vendor outside the stadium.

Newspapers have fretted that the evening match coincides with Earth Hour -- a climate change movement that sees millions turn off non-essential lights and appliances worldwide.

Bollywood superstar Amitabh Bachchan told his 19.9 million Twitter followers to watch the match with friends to save energy.

‘Support #EarthHour2016, watch #IndVSPak with friends on one screen, join campaign #TogethervsClimateChange’ he tweeted.

- Pakistan gears up -

In Pakistan, fans said the match was a chance to take revenge for their side's recent defeat in the Asia Cup in Bangladesh, where they lost to India and the hosts.

Few Pakistan fans are expected to attend the game, after the venue switch from Dharamsala to Kolkata disrupted travel plans, with some denied visas at the last minute. 

But that did not stop the atmosphere from amping up at home.

‘We hope to have a turnout of a couple of thousand spectators at our big screen,’ said Faisal Baig of the Port Grand complex in Karachi, Pakistan's bustling economic hub of 20 million people.

‘It feels wonderful to see people from different ethnic and political backgrounds become one nation and it only happens when Pakistan plays India,’ he added.

A sign outside the city's Bambino cinema declared regular movies cancelled as it shows the match instead, while the National Stadium is hosting a public screening.

‘We really want to see Pakistan win -- it's terrible to watch us lose,’ said Amjad Islam, an electrical engineering student at Indus University.

Many fans were pinning their hopes on Pakistan's most popular cricketer, captain Shahid Afridi, whose all-round performance against Bangladesh sealed a thumping win. 

The World T20 is set to be the 36 year-old's final tournament.

‘We want to see Afridi to perform regardless of the outcome,’ Umaima Tahir, a software engineering student told AFP.